Samacheer Kalvi 9th Science Guide Chapter 6 Light

Tamilnadu State Board New Syllabus Samacheer Kalvi 9th Science Guide Pdf Chapter 6 Light Text Book Back Questions and Answers, Notes.

Tamilnadu Samacheer Kalvi 9th Science Solutions Chapter 6 Light

9th Science Guide Light Text Book Back Questions and Answers

I. Choose the correct answer :

Question 1.
A ray of light passes from one medium to another medium. Refraction takes place when angle of incidence is
(a) 0°
(b) 45°
(c) 90°
Answer:
(c) 90°

Samacheer Kalvi 9th Science Guide Chapter 6 Light

Question 2.
is used as reflectors in torchlight.
(a) Concave mirror
(b) Plane mirror
(c) Convex mirror
Answer:
(a) Concave mirror

Question 3.
We can create enlarged, virtual images with
(a) concave mirror
(b) plane mirror
(c) convex mirror
Answer:
(a) concave mirror

Samacheer Kalvi 9th Science Guide Chapter 6 Light

Question 4.
When the reflecting surface is curved outwards the mirror formed will be
(a) concave mirror
(b) convex mirror
(c) plane mirror
Answer:
(b) convex mirror

Question 5.
When a beam of white light passes through a prism it gets
(a) reflected
(b) only deviated
(c) deviated and dispersedAnswer:
(c) deviated and dispersed

Question 6.
The speed of light is maximum in
(a) vacuum
(b) glass
(c) diamond
Answer:
(a) vacuum

Samacheer Kalvi 9th Science Guide Chapter 6 Light

II. State whether true or false. If false, correct the statement :

1. The angle of deviation depends on the refractive index of the glass.
Answer:
True

2. If a ray of light passes obliquely from one medium to another, it does not suffer any deviation.
Answer:
False.
Correct statement: If a ray of light passes obliquely from one medium to another, it bends and from the normal.

3. The convex mirror always produces a virtual, diminished and erect image of the object.
Answer:
True.

4. When an object is at the centre of curvature of concave mirror the image formed will be virtual and erect.
Answer:
False.
Correct statement: When an object is at the centre of curvature of concave mirror the image formed will be real and inverted.

5. The reason for brilliance of diamonds is total internal reflection of light.
Answer:
True.

Samacheer Kalvi 9th Science Guide Chapter 6 Light

III. Fill in the blanks :

1. In going from a rarer to denser medium, the ray of light bends ……………………….
Answer:
towards the normal

2. The mirror used in search light is ……………………….
Answer:
concave

3. The angle of deviation of light ray in a prism depends on the angle of . ……………………….
Answer:
incidence

4. The radius of curvature of a concave mirror whose focal length is 5cm is ………………………..
Answer:
10 cm

5. Large ……………………….mirrors are used to concentrate sunlight to produce heat in solar furnaces.
Answer:
concave

Samacheer Kalvi 9th Science Guide Chapter 6 Light

IV. Match- the following :

Ratio of height of image to height of object. Concave mirror
Used in hairpin bends in mountains. Total internal reflection
Coin inside water appearing slightly raised. Magnification
Mirage Convex mirror
Used as Dentist’s mirror. Refraction

Answer:

Ratio of height of image to height of object. Magnification
Used in hairpin bends in mountains. Convex mirror
Coin inside water appearing slightly raised. Refraction
Mirage Total internal reflection
Used as Dentist’s mirror. Concave mirror

V. Assertion & Reason :

Mark the correct choice as:
(a) If both assertion and reason are true and reason is the correct explanation.
(b) If both assertion and reason are true and reason is not the correct explanation.
(c) If assertion is true but reason is false.
(d) If assertion is false but reason is true

Samacheer Kalvi 9th Science Guide Chapter 6 Light

Question 1.
Assertion: For observing the traffic at a hairpin bend in mountain paths a plane mirror is preferred over the convex mirror and concave mirror.
Reason: A convex mirror has a much larger field of view than a plane mirror or a . concave mirror.
Answer:
(d) Assertion is false but reason is true

Question 2.
Assertion: The incident ray is directed towards the centre of curvature of spherical mirror. After reflection it retraces its path.
Reason : Angle of incidence (i) = Angle of reflection (r) = 0°.
Answer:
(a) Both assertion and reason are true and reason is the correct explanation

VI. Answer very briefly:

Question 1.
According to cartesian sign convention, which mirror and which lens has negative focal length?
Answer:
Concave mirror is having a negative focal length.

Samacheer Kalvi 9th Science Guide Chapter 6 Light

Question 2.
Name the mirror(s) that can give (i) an erect and enlarged image, (ii) same sized, inverted image.
Answer:
Concave mirror.

Question 3.
If an object is placed at the focus of a concave mirror, where is the image formed?
Answer:
The image will be formed at infinity as real and inverted.

Question 4.
Why does a ray of light bend when it travels from one medium to another?
Answer:
A ray of light bend when it travels from one medium to another due to the change in velocity of light in two different medium.

Question 5.
What is the speed of light in vacuum?
Answer:
The speed of light in vacuum is known to be almost exactly 300,000 km per second. In 1665 the Danish astronomer Ole Roemer first estimated the speed of light by observing one of the twelve moons of the planet Jupiter.

Samacheer Kalvi 9th Science Guide Chapter 6 Light

Question 6.
Concave mirrors are used by dentists to examine teeth. Why?
Answer:
As concave mirror produces virtual, erect and magnified images when an object is placed in

VII. Answer briefly :

Question 1.
a) Complete the diagram to show how a concave mirror forms the image of the object.
b) What is the nature of the image?
Samacheer Kalvi 9th Science Guide Chapter 6 Light 1
Answer:
a)
Samacheer Kalvi 9th Science Guide Chapter 6 Light 2

Samacheer Kalvi 9th Science Guide Chapter 6 Light
b) Real, inverted and magnified.

Question 2.
Pick out the concave and convex mirrors from the following and tabulate them. Rear-view mirror, Dentist’s mirror, Torch-light mirror, Mirrors in shopping malls, Make-up mirror.
Answer:

Concave Mirror Convex Mirror
Dentist’s mirror Rearview mirror
Torchlight mirror Mirrors in shopping malls
Makeup mirror

Question 3.
State the direction of the incident ray which after reflection from a spherical mirror retraces its path. Give a reason for your answer.
Answer:
When an incident ray is directed towards the centre of curvature, at all the points of the spherical mirror, the ray is always normal. Therefore, angle of incidence i = Angle of reflection r = 0°.

Question 4.
What is meant by magnification? Write its expression. What is its sign for real image and virtual image?
Answer:
Magnification is the increase in size of an image compared to true size.
Samacheer Kalvi 9th Science Guide Chapter 6 Light 3
(a) Negative sign – real image
(b) Positive sign – virtual image

Samacheer Kalvi 9th Science Guide Chapter 6 Light

Question 5.
Write the spherical mirror formula and explain the meaning of each symbol used in it.
Answer:
The expression relating the distance of the object u, distance of image v and focal length/of a spherical mirror is called the mirror equation. It is given as:
Mirror formula: \(\frac{1}{f}=\frac{1}{u}+\frac{1}{v}\)
Here, f – focal length of spherical mirror; u – distance of the objective; v – distance of the image.

VIII. Answer in detail :

Question 1.
a) Draw ray diagrams to show how the image is formed using a concave mirror, when the position of objeict is (i) at C (ii) between C and F (iii) between F and P of the mirror.
b) Mention the position and nature of image in each case.
Answer:
a) object At C
i)
Samacheer Kalvi 9th Science Guide Chapter 6 Light 4
(b) Position of an object: At C
Position of the image: At C

Nature of the image:
(i) Real
(ii) Inverted
(iii) Same size as the object

(ii) object At C and F
Samacheer Kalvi 9th Science Guide Chapter 6 Light 5
Position of the object: Between C and F
Position of the image: Beyond C

Nature of the image :
(i) Real
(ii) Inverted
(iii) Magnified

(iii) Object between F and P of the Mirror
Samacheer Kalvi 9th Science Guide Chapter 6 Light 6
Position of object : Between F and P
Position of the image : Behind the Mirror

Nature of the image :
(i) Virtual
(ii) Erect
(iii) Magnified

Samacheer Kalvi 9th Science Guide Chapter 6 Light

Question 2.
Explain with diagrams how refraction of incident light takes place from a) rarer to denser medium b) denser to rarer medium c) normal to the surface separating the two media.
Answer:
a) rarer to denser medium
When a ray of light travels from optically rarer medium to optically denser medium, it bends towards the normal.
Samacheer Kalvi 9th Science Guide Chapter 6 Light 7

b) denser to rarer medium
When a ray of light from an optically denser medium to an optically rarer medium it bends away from the normal.
Samacheer Kalvi 9th Science Guide Chapter 6 Light 8

c) normal to the surface separating the two media.
A ray of light incident normally on a denser medium it goes without any deviation.
Samacheer Kalvi 9th Science Guide Chapter 6 Light 9

Samacheer Kalvi 9th Science Guide Chapter 6 Light

IX. Numerical Problems:

Question 1.
A concave mirror produces three times magnified real image of an object placed at 7 cm in front of it. Where is the image located?
Answer:
Here given magnification m = 3
Object distance u = -7 cm
Magnification m = \(-\frac{v}{u}\) Real image
-3 = \(-\frac{v}{u}\)
3u = -v
v = 3u = 3 x 7 = 21 cm
The image will be formed at a distance of 21 cm in front of concave mirror from its pole.

Question 2.
Light enters from air into a glass plate having a refractive index of 1.5. What is the speed of light in glass?
Answer:
Refractive index of a glass plate μ = 1.5
Speed of light in vacuum is C = 3 x 108ms-1
Speed of light in glass V =?
Samacheer Kalvi 9th Science Guide Chapter 6 Light 10
speed of light in glass = 2 × 108ms-1

Samacheer Kalvi 9th Science Guide Chapter 6 Light

Question 3.
The speed of light in water is 2.25 × 108ms-1. If the speed of light in a vacuum is 3 × 108ms-1, calculate the refractive index of water.
Answer:
Speed of light in water V = 2.25 × 108ms-1
Speed of light in vacuum C = 3 × 108ms-1
Refractive index of water μ =?
Samacheer Kalvi 9th Science Guide Chapter 6 Light 11

X. Higher Order Thinking Skills.

Question 1.
Lightray emerges from water into the air. Draw a ray diagram indicating the change in its path in the water.
Answer:
Samacheer Kalvi 9th Science Guide Chapter 6 Light 12

Samacheer Kalvi 9th Science Guide Chapter 6 Light

Question 2.
When a ray of light passes from air into glass, is the angle of refraction greater than or less than the angle of incidence?
Answer:
Light bends towards the normal because glass is denser than air.
It bends towards normal since light has to travel with the lesser speed in the glass but within a short time.
r < i. The angle of refraction is less than the angle of incidence.

Question 3.
What do you conclude about the speed of light in diamond, if the refractive index of diamond is 2.41?
Answer:
Refractive index of diamond μ = 2.41
Samacheer Kalvi 9th Science Guide Chapter 6 Light 13
∴ Speed of light in a diamond (1.24 × 108ms-1) is less than the speed of light in air (3 × 108ms-1).
The refractive index of diamond is 2.42, it means that speed of light in air (vacuum) is 2.42 times the speed of light in a diamond.

Intext Activities

ACTIVITY – 1

Stand before the mirror in your dressing table or the mirror fixed in a steel almirah. Do you see your whole body? To see your entire body in a mirror, the mirror should be atleast half of your height. Height of the mirror= Your height/2.
Solution :
(i) If the height of a person is 5 feet, then he should use a plane mirror of 2Vi feet height and fix in a steal almirah.
(ii) Now if he stand before it his full body will be seen on the mirror because hight of the mirror = \(\frac{\text { Our hieight }}{2}\)

Samacheer Kalvi 9th Science Guide Chapter 6 Light

ACTIVITY – 2

Hold a concave mirror in your hand (or place it in a stand). Direct its reflecting surface towards the sun. Direct the light reflected by the mirror onto a sheet of paper held not very far from the mirror. Move the sheet of paper back and forth gradually until you find a bright, sharp spot of light on the paper. Position the mirror and the paper at the same location for few moments. What do you observe? Why does the paper catch fire?
Solution :
A concave mirror converges all the light rays coming from the Sun. All these light rays converge and meet at the focus of the mirror.
So, all the heat and light is focused on the principal focus (F). When a paper is kept at the focus (F), it starts burning, as this point is very hot.

ACTIVITY – 3

Take a convex mirror. Hold it in one hand. Hold a pencil close to the mirror in the upright position in the other hand. Observe the image of the pencil in the mirror. Is the image erect or inverted? Is it diminished or enlarged? Move the pencil slowly away from the mirror. Does the image become smaller or larger? What do you observe?
Samacheer Kalvi 9th Science Guide Chapter 6 Light 14
Solution :

  1. When a pencil is held in the upright position in front of a convex mirror, its diminished, erect image is formed which is virtual and therefore seen in the convex mirror.
  2. When the pencil is moved away from the convex mirror size of image becomes smaller and smaller but image remains erect.
  3. As we move away, the object from the convex mirror, image shifts towards the focus.

Samacheer Kalvi 9th Science Guide Chapter 6 Light

ACTIVITY – 4

Refraction of light at air-water interface
Put a straight pencil into a tank of water or beaker of water at an angle of 45° and look at it from one side and above. How does the pencil look now?
The pencil appears to be bent at the surface of water.
Solution :
Samacheer Kalvi 9th Science Guide Chapter 6 Light 15
Both the above activities are the result of refraction of light. The bending of light rays when they pass obliquely from one medium to another medium is called refraction of light.

9th Science Guide Light Additional Important Questions and Answers

I. Choose the correct answer :

Question 1.
A ray of light is incident towards a plane mirror at an angle of 30° with the mirror surface. What will be the angle of reflection?
(a) 45°
(b) 30°
(c) 90°
(d) 60°
Answer:
(d) 60°

Samacheer Kalvi 9th Science Guide Chapter 6 Light

Question 2.
A 10 mm long bin is placed vertically in front of a concave mirror. A 5 mm long image of the bin is formed at 30 cm in front of the mirror. The focal length of this mirror is
(a) -20cm
(b) -30cm
(c) -60cm
(d) -40cm
Answer:
(a) – 20cm

Question 3.
A ray of light as it travels from medium A to medium B refractive index of the medium B relative to medium A is (μB/ μA)
(a) \(\frac{\sqrt{3}}{\sqrt{2}}\)
(b) \(\frac{\sqrt{2}}{\sqrt{3}}\)
(c) \(\frac{{1}}{\sqrt{2}}\)
(d) \(\sqrt{2}\)
Answer:
(b) \(\frac{\sqrt{2}}{\sqrt{3}}\)

Samacheer Kalvi 9th Science Guide Chapter 6 Light

Question 4.
Under which of the following conditions a concave mirror can form an image larger than the actual object?
(a) when the object is kept at a distance equal to its radius of curvature.
(b) when object is kept at a distance less than its focal length.
(c) when object is placed between the focus and centre of curvature
(d) when object is kept at a distance greater than its radius of curvature.
Answer:
(c) when object is placed between the focus and centre of curvature

Question 5.
In torches, searchlights and head lights of vehicles the bulb is placed …………………………… of the concave mirror.
(a) between and F of the reflector
(b) Very near to F
(c) between F & C
(d) at C
Answer:
(b) Very near to F

Question 6.
A boy is standing at a distance of 3m in front of a plane mirror. The distance between the boy and his image is ………………….. m
(a) 4
(b) 2
(c) 3
(d) 6
Answer:
(c) 3

Samacheer Kalvi 9th Science Guide Chapter 6 Light

Question 7.
The image formed by a concave mirror is real, inverted and of the same size as that of the object the position of the object should be
(a) beyond C
(b) between C & F
(c) at C
(d) at F
Answer:
(c) at C

Question 8.
Which of the following has the highest refractive index
(a) air
(b) water
(c) diamond
(d) glass
Answer:
(c) diamond

Question 9.
The image formed by a plane mirror is
(a) real
(b) diminished
(c) enlarged
(d) laterally inverted
Answer:
(d) laterally inverted

Samacheer Kalvi 9th Science Guide Chapter 6 Light

Question 10.
The incident ray passing through ‘F of a mirror ………………….. after reflection
(a) passes through C
(b) passes through F
(c) passes parallel to the principal axis
(d) passes through the pole
Answer:
(c) passes parallel to the principal axis

Question 11.
The incident ray passing through C of a mirror ………………….. after reflection.
(a) passes through C
(b) passes through F
(c) passes through P
(d) parallel to the principal axis
Answer:
(a) passes through C

Question 12.
The incident ray parallel to the principal axis of a mirror ………………….. after reflection.
(a) passes through C
(b) passes through F
(c) passes through P
(d) reverts back in the opposite direction
Answer:
(b) passes through F

Samacheer Kalvi 9th Science Guide Chapter 6 Light

Question 13.
According to sign convention the distance of the object.
(a) is always positive
(b) is always negative
(c) maybe positive or negative
(d) is equal to object height.
Answer:
(b) is always negative

Question 14.
According to sign convention the distance of the image.
(a) is always positive
(b) is always negative
(c) maybe positive or negative
(d) is equal to image height
Answer:
(c) maybe positive or negative

Question 15.
Total internal reflection will occur if the angle of reflection is
(a) 45°
(b) 60°
(c) 90°
(d) 99°
Answer:
(d) 99°

Samacheer Kalvi 9th Science Guide Chapter 6 Light

Question 16.
Magnification for the………………….. image is always …………………..
(a) real, positive
(b) real, negative
(c) virtual, negative
(d) virtual, positive
Answer:
(b) real, negative

Question 17.
If magnification is +1.5. The image is …………………..
(a) erect
(b) diminished
(c) real
(d) invected
Answer:
(a) erect

Question 18.
The refractive index of a denser medium with respect to rarer medium is
(a) 1
(b) greater than 1
(c) less than 1
(d) negative
Answer:
(b) greater than 1

Samacheer Kalvi 9th Science Guide Chapter 6 Light

Question 19.
We can see objects because of
(a) reflection
(b) refraction
(c) transmission
(d) diffraction
Answer:
(a) reflection

Question 20.
The image formed by a convex mirror is always
(a) real (b) enlarged
(c) virtual & enlarged
(d) diminished
Answer:
(d) diminished

Samacheer Kalvi 9th Science Guide Chapter 6 Light

Question 21.
As you move an object always from a convex mirror, its image becomes…………………..
and moves towards
(a) smaller, infinity
(b) smaller, focus
(c) enlarged, infinity
(d) enlarged, focus
Answer:
(b) smaller, focus

Question 22.
For a spherical mirror ………………….. is true.
(a) f = 2R
(b) R = 2f
(c) fR = 2
(d) fR = \(\frac { 1 }{ 2 }\)
Answer:
(b) R = 2f

Samacheer Kalvi 9th Science Guide Chapter 6 Light

Question 23.
The mirror formula is…………………..
Samacheer Kalvi 9th Science Guide Chapter 6 Light 16
Answer:
(c) \(\frac{1}{f}=\frac{1}{u}+\frac{1}{v}\)

Question 24.
For a plane mirror, magnification m =
(a) 0
(b) 1
(c) ± 1
(d) ≤0
Answer:
(b) 1

Question 25.
Magnification for convex mirror is
(a) always positive
(b) always negative
(c) some times positive
(d) 1
Answer::
(a) always positive

Question 26.
If the angle of incidence i = 0, the angle of reflection r =
(a) 0°
(b) 90°
(c) 180°
(d) 45°
Answer:
(a) 0°

Samacheer Kalvi 9th Science Guide Chapter 6 Light

Question 27.
Refractive index of a medium is …………………..
(a) speed of light in air to speed of light in vacuum
(b) speed of light in vacuum to speed of light in air
(c) focal length to object distance
(d) speed of light in the medium × speed of light in the air
Answer:
(a) speed of light in air to speed of light in vacuum

Question 28.
Bending of light as it passes from one medium to another is called
(a) reflection
(b) diffraction
(c) refraction
(d) deviation
Answer:
(c) refraction

Question 29.
Ratio of sine of angle of incidence to sine of angle of refraction is ………………….
(a) gravitational law
(b) law of reflection
(c) law of refraction
(d) snell’s law.
Answer:
(d) snell’s law

Samacheer Kalvi 9th Science Guide Chapter 6 Light

Question 30.
Entire light is reflected back into denser medium is called
(a) total internal reflection
(b) refraction
(c) reflection
(d) total external refraction.
Answer:
(a) total internal reflection

Question 31.
Outer concentric shell in optic fiber is called
(a) cladding
(b) core
(c) mantel
(d) coat
Answer:
(a) cladding

Question 32.
When light is going from a denser to a less dense medium, the critical angle is the angle of incidence for which the angle of refraction is
(a) 48°
(b) 90°
(c) 42°
(d) 51°
Answer:
(b) 90°

Question 33.
A bundle of glass threads, each of which is capable of transmitting messages using light waves is called
(a) microscope
(b) convex
(c) periscope
(d) optic fibre
Answer:
(d) optic fibre

Samacheer Kalvi 9th Science Guide Chapter 6 Light

Question 34.
A ray of light travelling in medium 1 strikes and travels into another transparent medium 2. If the speed of light is greater in medium 1, the ray will
(a) refract towards the normal
(b) have an angle of incidence smaller than be angle of refraction
(c) refract away from the normal
(d) undergo total internal reflection
Answer:
(a) refract towards the normal

Question 35.
A ray of light travels from air into a glass block as shown. It makes an angle of 30° with the surface of the block. If the refractive index of the glass is 1.5, what will be the angle of refraction?
Samacheer Kalvi 9th Science Guide Chapter 6 Light 17
(a) 35.26°
(b) 1.30°
(c) 48.59°
(d) 19.47°
Answer:
(d) 19.47°

Question 36.
The field of view is maximum for …………………
(* FOV is the extent of the observable area that is seen at any given instant)
(a) plane mirror
(b) concave mirror
(c) convex mirror
Answer:
(c) convex mirror

Samacheer Kalvi 9th Science Guide Chapter 6 Light

Question 37.
A real and enlarged image can be obtained by using a
(a) convex mirror
(b) plane mirror
(c) concave mirror
Answer:
(c) concave mirror

Question 38.
Which of the following statements about total internal reflection is true?
(a) angle of incidence should be greater than the critical angle
(b) light must travel from a medium of higher refractive index to a medium of lower refractive index
(c) both (a) and (b)
Answer:
(c) both (a) and (b)

Question 39.
The focal length of a concave mirror is 5cm. Its radius of curvature is
(a) 5 cm
(b) 10 cm
(c) 2.5 cm
Answer:
(b) 10 cm

Samacheer Kalvi 9th Science Guide Chapter 6 Light

II. Fill in the blanks :

1. The ratio of the sine of the angle of incidence to the sine of …………………is constant.
Answer:
angle of refraction

2. A spherical mirror whose reflecting surface is curved outwards is called ………………… mirror.
Answer:
convex

3. All distances parallel to the principal axis are measured from the ………………… of the
mirror.
Answer:
pole

4. A negative sign in the value of magnification indicates that the image is …………………
Answer:
real

5. Light is refracted or bent while going from one medium to another because of its ………………… changes.
Answer:
speed

Samacheer Kalvi 9th Science Guide Chapter 6 Light

III. State whether true or false. If false, correct the statement:

1. The critical angle is defined as the angle of incidence at which the total internal reflection starts to occur.
Answer:
True.

2. The angle of incidence is equal to the angle of reflection for perfect reflection.
Answer:
True.

3. The image formed in a plane mirror is always inverted.
Answer:
False.
Correct statement: The image formed in a plane mirror is always erect.

4. A star appears twinkling into the sky because of the reflection of light by the atmosphere
Answer:
False.
Correct statement: A star appears twinkling into the sky because of the refraction of light by the atmosphere.

5. Mirage is an example of refraction and total internal reflection of light.
Answer:
True.

Samacheer Kalvi 9th Science Guide Chapter 6 Light

6. Optical Fibres are based on the phenomenon of dispersion
Answer:
False.
Correct statement: Optical Fibres are based on total internal reflection.

7. A water tank appears shallower when it is viewed from the top due to refraction.
Answer:
True.

8. Twinkling of stars and Mirage are the two phenomena occurring due to refraction.
Answer:
True.
Twinkling of stars and Mirage.

9. Angle of incidence is zero if a ray of light is incident normal to be surface separating the low media.
Answer:
True.

10. A real image is inverted and can be caught on the screen.
Answer:
True.

11. The minimum length of the mirror required to see the full image of the person is half ‘ of his height.
Answer:
true.

Samacheer Kalvi 9th Science Guide Chapter 6 Light

12. The pencil appears to be bent at the surface of the water is due to refraction.
Answer:
True.

13. The speed of light decreases in a denser medium, light bends towards the normal.
Answer:
True.

14. If the object is at infinity in front of a convex mirror the image is formed at infinity.
Answer:
False.
Correct statement: The image is formed at F, behind the mirror

15. An object is placed at a distance of 3cm from a plane mirror. The distance of the object and image is 3cm.
Answer:
False.
Correct statement: The distance of the object and image is 6 cm.

16. The distance from centre of curvature of the mirror to the pole is called the focal length of the mirror.
Answer:
False.
Correct statement: The distance between the centre of the mirror and the focal point of the mirror is called the focal length of a mirror.

Samacheer Kalvi 9th Science Guide Chapter 6 Light

17. Light is one of the slowest travelling energy with a speed of 3 × 10-8ms-1
Answer:
False.
Correct statement : (Light is one of the fastest travelling energy with a speed of 3 × 10-8ms-1

18. The angle of incidence at which the angle of refraction is Q£ is called the critical angle.
Answer:
False.
Correct statement: The angle of incidence at which the angle of refraction is 90° is called the critical angle.

IV. Match the following :

Question 1.

Column I Column II
(i) A plane mirror (a) Image is erect & smaller in size than the object.
(ii) A concave mirror (b) Image is erect & of the same size as of the object.
(iii) A convex (c) Used by dentists to see an enlarged images of teeth.
(d) Can form images of objects spread over a large area.

Answer:

Column I Column II
(i) A plane mirror (b) Image is erect & of the same size as of the object.
(ii) A concave mirror (c) Used by dentists to see enlarged image of teeth.
(iii) A convex (d) Can form image of objects spread over a large area.

Question 2.

Column I Column II
(i) r > 90 (a) Light gazes the surface of separation between two mode.
(ii) r = 90 (b) No refraction.
(iii) r < 90 (c) Refracted ray away from the normal

Answer:

Column I Column II
(i) r > 90 (b) No refraction.
(ii) r = 90 (a) Light gazes the surface of separation between two mode.
(iii) r < 90 (c) Refracted ray away from the normal

Samacheer Kalvi 9th Science Guide Chapter 6 Light

Question 3.

Column I Column II
(i) plane mirror (a) Focal length is positive.
(ii) concave (b) Focal length is negative.
(iii) convex (c) Focal length is infinity.
(iv) Real image (d) Magnification if positive value.
(v) Virtual image (e) Magnification if negative value.

Answer:

Column I Column II
(i) plane mirror (c) Focal length is infinity.
(ii) concave (b) Focal length is negative.
(iii) convex (a) Focal length is positive.
(iv) Real image (e) Magnification if negative value.
(v) Virtual image (d) Magnification if positive value.

Question 4.
Samacheer Kalvi 9th Science Guide Chapter 6 Light 18
Answer:
Samacheer Kalvi 9th Science Guide Chapter 6 Light 19

V. Assertion & Reason Type :

(a) If both assertion & reason are true and the reason is the correct explanation of the assertion.
(b) If both assertion & reason are true but the reason is not correct explanation of the assertion.
(c) If assertion is true but reason is false.
(d) If assertion & reason both are false.
(e) If assertion is false but reason is true.

Samacheer Kalvi 9th Science Guide Chapter 6 Light

Question 1.
Assertion : The air bubble shines in water.
Reason : Air bubble shines due to refraction of light.
Answer:
(c) If assertion is true but reason is false

Question 2.
Assertion : The focal length of the mirror is /and distance of the object from the
focus is V then the magnification of the mirror will be \(\left(\frac{f}{f-u}\right)\)
Samacheer Kalvi 9th Science Guide Chapter 6 Light 20
Answer:
(a) Both assertion & reason are true and the reason is the correct explanation of the assertion

Question 3.
Assertion : When an object is placed between two plane mirrors, then all the images found are of equal brightness.
Reason : Only two images are obtained in case of plane-parallel mirrors.
Answer:
(d) Assertion & reason both are false

Samacheer Kalvi 9th Science Guide Chapter 6 Light

Question 4.
Assertion: The mirrors used in torch lights are parabolic not concave.
Reason: The image formed by concave mirror is always virtual.
Answer:
(c) Assertion is true but reason is false

Question 5.
Assertion : The nature of the image depends on the size of the mirror.
Reason : Small mirrors always form a virtual image.
Answer:
(d) Assertion & reason both are false

Question 6.
Assertion : A real image cannot be produced by plane or convex mirror.
Reason : The focal length of a convex mirror is always taken as possitive.
Answer:
(e) Assertion is false but reason is true

Samacheer Kalvi 9th Science Guide Chapter 6 Light

VI. Answer very briefly :

Question 1.
Which is optically denser out of the two medium M1& M2 having the refractive indices = 1.71 and 1.36 respectively?
Answer:
M1
Reason: Optical density increases as the value of the refractive index increases.

Question 2.
Two medium with refractive index 1.31 & 1.50 is given. In which case (i) Bending of light is more and (ii) speed of light is more.
Answer:
(i) 1.50 – Bending is more
(ii) 1.31 – Speed is more

Samacheer Kalvi 9th Science Guide Chapter 6 Light

Question 3.
Under what circumstances there won’t be any refraction of light when it enters from one medium to another?
Answer:

  • When light incident at 90°, it will not bend.
  • When light passes from denser medium to rarer medium and if it is incident at an angle greater than the critical angle, it will reflect but will not refract.

Question 4.
A ray of light traveling in air enters obliquely into water. Does the light ray bend towards the normal or away from the normal? Why?
Answer:

  • When a ray of light travels from air into water obliquely, it bends towards the normal.
  • This is because water is optically denser than air.
  • On entering water, speed of light decreases and the light bends towards normal.

Question 5.
List down the uses of concave mirror.
Answer:
Concave mirrors are used :

  • As Shaving mirror.
  • As Reflectors in automobile headlights & torches.
  • By dentists to see large images of the teeth of patients.
  • To produce heat in solar furnaces.

Samacheer Kalvi 9th Science Guide Chapter 6 Light

Question 6.
What are the characteristics of the image formed on a plane mirror?
Answer:

  • Image is upright.
  • Size of the image is the same as the size of the object.

Question 7.
State the laws of reflection of light.
Answer:

  • The incident ray, the normal at the point of incidence and the reflected ray, all lie in the same plane.
  • Angle of incidence is equal to the angle of reflection.

Question 8.
Describe the nature of images formed by plane mirrors.
Answer:

  • It is always virtual and erect.
  • Its size is equal to that of the object
  • It is formed at the same distance behind the mirror as the object is in front of the mirror.
  • It is laterally inverted.

Samacheer Kalvi 9th Science Guide Chapter 6 Light

Question 9.
What is lateral inversion in a plane mirror?
Answer:
It means the apparent reversal of left and right in the mirror image compared with the object.

Question 10.
Explain why a ray of light passing through the centre of curvature of a concave mirror, gets reflected along with the same pattern.
Answer:
The ray passing through the centre of curvature incident to the mirror along its normal so < i = < r = 0
∴ The ray retraces its pattern

Question 11.
How tall does a mirror have to be to fit an entire person’s body?
Answer:
The height of the mirror should behalf of the person’s height regardless of the distance of the person from the mirror.

Question 12.
What is concave and convex mirror?
Answer:

  • If the reflecting surface is curved inwards that is called concave mirror.
  • The reflecting surface is curved outwards, then it is called convex mirror.

Samacheer Kalvi 9th Science Guide Chapter 6 Light

Question 13.
Define principal focus of concave mirror.
Answer:
Principal focus (F): The point on the principal axis of the spherical mirror where the rays of light parallel to the principal axis meet or appear to meet after reflection from the spherical mirror.

Question 14.
What is focal length (f) of a mirror?
Answer:
The distance between the pole (P) and the principal focus (F) of the spherical mirror is called the focal length.
f = \(\frac { R }{ 2 }\) , where R is the radius of curvature of the mirror.

Question 15.
Define Radius of curvature.
Answer:
The radius of the hollow sphere of which the spherical mirror forms a part is called the radius of curvature (R)
R = 2 × focal length

Samacheer Kalvi 9th Science Guide Chapter 6 Light

Question 16.
What is “aperture”?
Answer:
The diameter of the circular rim of the mirror is called the aperture of the mirror. It is the entire area of the reflecting surface of the mirror.

Question 17.
Distinguish between real & virtual image.
Answer:
Real :

  1. Light rays that come from an object actually meet after reflection.
  2. It can be obtained on a screen
  3. Image is inverted

Virtual :

  1. Light comes from an object does not actually meet but appears to meet.
  2. It cannot be obtained on the screen.
  3. The image is erect.

Samacheer Kalvi 9th Science Guide Chapter 6 Light

Question 18.
What do you mean by linear magnification?
Answer:
It is defined as the ratio of the height of the image (hi) to the height of the object (ho).
\(m=\frac{h_{i}}{h_{o}}(\text { or }) \quad m=-\frac{v}{u}\)

Question 19.
Which kind of mirrors are used in the shaving mirror? Why?
Answer:
Cancave mirror, to get magnified image. When a cancave mirror is held near the face (between the pole and focus of the mirror) then an upright and magnified image is seen.

Question 20.
Which mirror is used as a reflector? Why?
Answer:

  • Concave mirrors are used as reflectors in torches, vehicle headlights and searchlights.
  • To get a powerful parallel beam of light.

Question 21.
Write the uses of cancave mirror
Answer:

  1. As a shaving mirror: Magnified face will be seen
  2. As a dentist head mirror: Focuses the lights on to see a small area of the body (teeth, throat, etc.)
  3. As reflectors: To get a powerful beam of light
  4. In solar heaters: To focus sun light for heaters

Question 22.
What do you observe when an object is placed anywhere between P and infinity in front of a convex mirror?
Answer:

  • The image is formed behind the mirror between the pole (P) and focus (F).
  • Virtual and erect image.
  • Diminished image.

Samacheer Kalvi 9th Science Guide Chapter 6 Light

Question 23.
What is the nature of the image formed by a concave mirror if the magnification produced by the mirror is +4?
Answer:
Positive sign of magnification indicates that image is virtual, erect and enlarged.

Question 24.
Between which two points of a concave mirror should an object be placed to obtain a magnification of -2?
Answer:
Negative sign of magnification indicates that image is real and inverted. Sign of image is magnified (enlarge)
∴ Object is placed between F and C.

Question 25.
To obtain an image twice the size of the object, between which two points related to a concave mirror should an object be placed?
Answer:
Between F (principal focus) and C centre of curvature.
Real Image.

Question 26.
Draw a ray diagram and also state the position the relative size and nature of image formed by a concave mirror, when an object is placed at C.
Answer:
Image Position: At C, itself
Size: Same size
Nature : (i) Real
(ii) Inverted
Samacheer Kalvi 9th Science Guide Chapter 6 Light 21

Samacheer Kalvi 9th Science Guide Chapter 6 Light

Question 27.
Why a pencil partly immersed in water appears to be bent at the water surface.
Answer:
The pencil dipped in water appears bent due to the refraction of light.
The angle of refraction depends on the refractive index of the medium.

Question 28.
How should a ray of light be incident on a rectangular glass slab so that it comes out from the opposite side of the slab without being displaced?
Answer:
Along the normal to the surface or at an angle of incidence of i = 0.

Question 29.
Why a convex mirror is preferred for rearview mirrors in cars?
Answer:

  • It always forms virtual, erect, and diminished images.
  • The field of view increases.

Question 30.
List four properties of the image formed by a convex mirror.
Answer:

  • Always formed behind the mirror between P & F.
  • Virtual & erect
  • Size is always smaller than the object.
  • Magnification is always positive.

Samacheer Kalvi 9th Science Guide Chapter 6 Light

Question 31.
List four properties of the image formed by the concave mirror when the object is placed between F & P
Answer:

  • The image formed behind the mirror
  • Enlarged
  • Virtual
  • Erect

Question 32.
What is meant by the refraction of light?
Answer:
Light does not travel in the same direction in all media. It changes its direction, the bending of a light ray when it passes from one medium to another is called refraction of light.

Question 33.
State the laws of refraction of light.
Answer:
(i) The incident ray, the refracted ray, and the normal to the interface of two transparent media at the point of incidence, all lie in the same plane.

(ii) The ratio of the sine of the angle of incidence to the sine of the angle of refraction is a constant for a light of a given colour and for the given pair of media. This law is also known as Snell’s law of refraction.
If i is the angle of incidence and r is the angle of refraction, then \(\frac{\sin i}{\sin r}[latex] = constant
This constant is called the refractive index of the second medium with respect to the first medium. T

Samacheer Kalvi 9th Science Guide Chapter 6 Light

Question 34.
Define refractive index & write its unit.
Answer:
The refractive index of the second medium with respect to the first medium is defined as the ratio of the sine of the angle of incidence in the first medium to the sine of the angle of refraction in the second medium.
Unit: The refractive index has no unit as it is the ratio of two similar quantities

Question 35.
Define refractive index in terms of speed of light.
Answer:
The refractive index of a medium is also defined in terms of speed of light in different media
Samacheer Kalvi 9th Science Guide Chapter 6 Light 22

Question 36.
What is total internal reflection?
Answer:
Total internal reflection: When the angle of incidence exceeds the value of the critical angle, the refracted ray is not possible, since r > 90°, the ray is totally reflected back to the same medium (denser medium). This is called as total internal reflection.

Samacheer Kalvi 9th Science Guide Chapter 6 Light

Question 37.
Define the critical angle.
Answer:
The angle of incidence at which the angle of refraction is 90° is called the critical angle.

Question 38.
What are the conditions to achieve total internal reflection?
Answer:

  • Light must travel from denser medium (Water) to rarer medium (Air).
  • The angle of incidence inside the denser medium must be greater than that of the critical angle.

Question 39.
What is mirage? How it occurs?
Answer:

  • Mirage is an optical illusion caused by the refraction of light from the sky by heated air.
  • The air near the ground becomes hotter than the air at higher levels.
  • The refractive index of air increases with its density. Hotter air is less dense, and has smaller refractive index than cooler air.
  • If the air currents are small, that is, the air is still, the optical density of different layers of air increases with height.
  • As a result, light from an object such as a car passes through a medium whose refractive index decreases towards the ground.
  • Thus, a ray of light from such an object successively bends away from the normal and undergoes total internal reflection, if the angle of incidence for the air near the ground exceeds the critical angle.

Samacheer Kalvi 9th Science Guide Chapter 6 Light

Question 40.
How do twinkling stars occur? (or) what is the cause of the twinkling of stars?
Answer:
Refraction of light:

  • Light from a star is refracted as it passes through our atmosphere because the light
    passes rapidly through moving cells of air with different densities, temperatures, etc.
  • These cells bend light by different amounts and make the apparent position of the star move around. This movement is seen as twinkling.

Question 41.
What is the phenomenon used in optical fibre? Explain.
Answer:

  • Optical fibres are extensively used for transmitting audio and video signals through long distances.
  • Optical fibres too make use of the phenomenon of total internal reflection.
  • Optical fibers are fabricated with high-quality composite glass/quartz fibres.
    Each fibres consists of a core and cladding. The refractive index of the material of the core is higher than that of the cladding.

When a signal in the form of light is directed at one end of the fibre at a suitable angle, it undergoes repeated total internal reflection along the length of the fibre and finally comes out at the other end. Optical fibres are extensively used for transmitting and receiving electrical signals which are converted to light between the ends of the fibre, over long distances.

Samacheer Kalvi 9th Science Guide Chapter 6 Light

Question 42.
Write any two uses of total internal reflection.
Answer:

  1. Spectacular brilliance of diamonds.
  2. Transmission of audio and video signals to long-distance through optical fibres.

Question 43.
What are the examples of total internal reflection in nature?
Answer:

  1. Mirage
  2. Twinkling of stars

Question 44.
Give two examples of the transparent medium that are denser than air.
Answer:
Water, glass.

Question 45.
A coin in a glass beaker appears to rise as the beaker is slowly filled with water why?
Answer:
Refraction of light at the air-water interface.

Samacheer Kalvi 9th Science Guide Chapter 6 Light

Question 46.
Name the spherical mirror(s) that has/have
(i) Virtual principal focus
(ii) Real principal focus
Answer:
(i) Convex
(ii) Concave.

VII. Long Answers

Question 1.
List the sign conventions for reflection of light by spherical mirrors.
(i) Write the formula for the spherical mirror.
(ii) Mirror Equation
Answer:
Samacheer Kalvi 9th Science Guide Chapter 6 Light 23
(i)

  • The object is always placed on the left side of the mirror.
  • All distances are measured from the pole of the mirror.
  • Distances measured in the direction of light are taken as positive (along + X-axis) and those measured in the opposite direction are taken as negative (along – X-axis).
  • All distances measured perpendicular to and above the principal axis (along + Y-axis) are considered to be positive.
  • All distances measured perpendicular to and below the principal axis (along – Y-axis) are considered to be negative. Cartesian sign conventions are used to derive mirror formula and do simple calculations.

Samacheer Kalvi 9th Science Guide Chapter 6 Light 24

(ii) Mirror Equation
The expression relating the distance of the object u, a distance of image v, and focal length f of a spherical mirror is called the mirror equation.
[latex]\frac{1}{f}=\frac{1}{u}+\frac{1}{v}\)

f – focal length of a spherical mirror
u – Distance of the object
v – Distance of the image

Linear Magnification:

It can be defined as the ratio of the height of the image (hi) to the height of the object (ho)
m = \(\frac{h_{i}}{h_{o}}(\text { or }) \frac{-v}{u}\)
hi = height of the image
ho = height of the object

Question 2.
State the type of mirror used as
(i) Convex mirror
(ii) Concave mirror
Answer:
(i) Convex mirror :

  • It gives a wide field of view
  • It produces erect and small size image of the object. [As the vehicles approach the driver from behind, the size of the image increases. When vehicles are moving away from the driver, the image size decreases]

(ii) Concave mirror:
To see a large size image of the face.
When the object lies in between pole and principal focus, it forms a virtual, erect and enlarged image.

Samacheer Kalvi 9th Science Guide Chapter 6 Light

Question 3.
Write the rules for the construction of image by Concave mirrors, along with ray diagram. .
Answer:
(i) Rule 1 : A ray passing through the centre of curvature is reflected back along its own path.
Samacheer Kalvi 9th Science Guide Chapter 6 Light 25

(ii) Rule 2 : A ray parallel to the principal axis passes through the focus after reflection.
Samacheer Kalvi 9th Science Guide Chapter 6 Light 26

(iii) Rule 3 :A ray passing through the focus gets reflected and travels parallel to the principal axis.
Samacheer Kalvi 9th Science Guide Chapter 6 Light 27

(iv) Rule 4 : A ray AP incident at the pole of the mirror gets reflected along a path PB
such that the angle of incidence APC is equal to the angle of reflection BPC.
Samacheer Kalvi 9th Science Guide Chapter 6 Light 28

Samacheer Kalvi 9th Science Guide Chapter 6 Light

Question 4.
Describe the nature and location of the images for the different positions of object which is placed in front of the concave mirror.
Answer:
Samacheer Kalvi 9th Science Guide Chapter 6 Light 29
Samacheer Kalvi 9th Science Guide Chapter 6 Light 30

VIII. Higher-Order Thinking Skills :

Question 1.
M = 2.42 for diamond. What is the meaning of this statement in relation to the speed of light?
Answer:
It means that light travels 2.42 times faster in a vacuum than in a diamond.

Question 2.
A convex mirror is in water. What should be the change in its focal length?
Answer:
No change. The focal length of a convex mirror does not depend on the nature of the medium.

Samacheer Kalvi 9th Science Guide Chapter 6 Light

Question 3.
Are the laws of reflection true in the case of irregular reflection?
Answer:
Yes, at the point of incidence both laws of reflection will hold good.

Samacheer Kalvi 9th Science Guide Chapter 4 Electric Charge and Electric Current

Tamilnadu State Board New Syllabus Samacheer Kalvi 9th Science Guide Pdf Chapter 4 Electric Charge and Electric Current Text Book Back Questions and Answers, Notes.

Tamilnadu Samacheer Kalvi 9th Science Solutions Chapter 4 Electric Charge and Electric Current

9th Science Guide Electric Charge and Electric Current Text Book Back Questions and Answers

I. Choose the correct answer:

Question 1.
In current electricity, a positive charge refers to,
(a) presence of electron
(b) presence of proton
(c) absence of electron
(d) absence of proton
Answer:
(c) absence of electron

Samacheer Kalvi 9th Science Guide Chapter 4 Electric Charge and Electric Current

Question 2.
Rubbing of comb with hair
(a) creates electric charge
(b) transfers electric charge
(c) either (a) or (b)
(d) neither (a) nor (b)
Answer:
(b) transfers electric charge

Question 3.
Electric field lines ……………….. from positive charge and ……………………..in negative charge.
(a) start; start
(b) start; end
(c) start: end
(d) end; end
Answer:
(b) or (c) start, end

Question 4.
Potential near a charge is the measure of its……………to bring a positive charge at that point.
(a) force
(b) ability
(c) tendency
(d) work
Answer:
(d) work

Samacheer Kalvi 9th Science Guide Chapter 4 Electric Charge and Electric Current

Question 5.
Heating effect of current is called,
(a) Joule heating
(b) Coulomb heating
(c) Voltage heating
(d) Ampere heating
Answer:
(a) Joule heating

Samacheer Kalvi 9th Science Guide Chapter 4 Electric Charge and Electric Current

Question 6.
In an electrolyte, the current is due to the flow of
(a) electrons
(b) positive ions
(c) both (a) and (b)
(d) neither (a) nor (b)
Answer:
(c) both (a) and (b)

Question 7.
Electroplating is an example of
(a) heating effects
(b) chemical effects
(c) flowing effects
(d) magnetic effect
Answer:
(b) chemical effect

Samacheer Kalvi 9th Science Guide Chapter 4 Electric Charge and Electric Current

Question 8.
Resistance of a wire depends on,
(a) temperature
(e) nature of material
(b) geometry
(d) all the above
Answer:
(d) all the above

II. Match the following

1. Electric Charge (a) ohm
2. Potential difference (b) ampere
3. Electric field (c) coulomb
4. Resistance (d) newton per coulomb
5. Electric current (e) volt

Answer:
1 – c, 2 – e, 3 – d, 4 – a, 5 – b

III. State whether true or false. If false, correct the statement:

1. Electrically neutral means it is either zero or equal positive and negative charges.
Answer:
True.

2. Ammeter is connected in parallel in an electric circuit.
Answer:
False.
Correct statement: Ammeter is connected in series in an electric circuit.

3. The anode in the electrolyte is negative.
Answer:
False.
Correct statement: The anode in the electrolyte is positive.

Samacheer Kalvi 9th Science Guide Chapter 4 Electric Charge and Electric Current

4. Current can produce the magnetic field.
Answer:
True.

IV. Fill in the blanks :

1. Electrons move from …………….. potential to …………….. potential.
Answer:
lower, higher

Samacheer Kalvi 9th Science Guide Chapter 4 Electric Charge and Electric Current

2. The direction opposite to the movement of electron is called …………….. current.
Answer:
conventional

3. The e.m.f of a cell is analogues to a pipeline.
Answer:
water pump

4. The domestic electricity in India is an ac with a frequency of Hz.
Answer:
50

Samacheer Kalvi 9th Science Guide Chapter 4 Electric Charge and Electric Current

V. Conceptual Questions:

Question 1.
A bird sitting on a high power electric line is still safe. How?
Answer:
Birds don’t get shocked when they sit on electrical wires because they are not good conductors of electricity. Electricity flowing through a single power line at 35,000 volts will continue along the path of least resistance and bypass birds because there is no difference in electrical potential.

Question 2.
Does a solar cell always maintain the potential across its terminals constant? Discuss.
Answer:
Solar cell delivers a constant current for any given illumination level, while the voltage is determined by the load resistance. Potential in a solar cell depends on the intensity of solar radiation. Since the intensity of solar radiation is not always constant, the potential across its terminal is also not constant.

Samacheer Kalvi 9th Science Guide Chapter 4 Electric Charge and Electric Current

Question 3.
Can electroplating be possible with the alternating current?
Answer:
Electroplating is a process where there is a continuous flow of ions for the deposition of copper, which is not possible in an Alternating current. Therefore, electroplating is possible with DC only, for the sake of perfectness and homogeneity of the electroplating.

Samacheer Kalvi 9th Science Guide Chapter 4 Electric Charge and Electric Current

VI. Answer the following:

Question 1.
On what factors does the electrostatic force between two charges depend?
Answer:
The electrostatic force between two charges depend on the following factors;

  • value of charges on them,
  • distance between them, and
  • nature of medium between them.

Question 2.
What are the electric lines of force?
Answer:
The lines representing the electric field are called electric lines of force.

Question 3.
Define electric field.
Answer:
The electric lines of force are straight or curved paths along which a unit positive charge tends to move in the electric field.

Samacheer Kalvi 9th Science Guide Chapter 4 Electric Charge and Electric Current

Question 4.
Define electric current and give its unit.
Answer:
The electric current is defined as the rate of flow of electric charge through any section of a conductor.
Electric current I = Q/t
Its unit is Cs-1
Its SI unit: ampere (A).

Question 5.
State Ohm’s law.
Answer:
Ohm’s law states that electric potential difference across two points in an electrical circuit is directly proportional to the current passing through it. That is V ~ I
The proportionality constant is the resistance (R) offered between the two points.
Hence, Ohm’s law is written as V = RI (or) V = IR
Where, V is the potential difference in volt (V), I is the current flow in ampere (A), R is the resistance in ohm (Ω)

Question 6.
Name any two appliances which work under the principle of heating effect of current.
Answer:
Electric heating appliances like an iron box, water heater, toaster, etc.

Samacheer Kalvi 9th Science Guide Chapter 4 Electric Charge and Electric Current

Question 7.
How are the home appliances connected in general, in series or parallel? Give reasons.
Answer:
The home appliances are connected in parallel. This is because, when the appliances are connected in parallel, each of them can be switched on and off independently. This is a feature that is essential in house wiring. Also, if the appliances were wired in series, the potential difference across each appliance would vary depending on the resistance of the appliance.

Question 8.
List the safety features whilehandling electricity.
Answer:
(i) Ground connection: The metal bodies of all the electrical appliances are to be connected to the ground by means of a third wire apart from the two wires used for electrical connection.

(ii) Trip switch: It is an electromechanical device which does not allow a current beyond a particular value by automatically switching off the connection.

(iii) Fuse: A fuse is another safety mechanism which works on the joule heating principle.

Samacheer Kalvi 9th Science Guide Chapter 4 Electric Charge and Electric Current

VII. Exercises:

Question 1.
Rubbing a comb on hair makes the comb get – 0.4C.
(a) Find which material has lost electron and which one gained it.
(b) Find how many electrons are transferred in this process.
Answer:
a. Comb gained electrons. Dry hair lost an electron
b. No. of electrons transferred = -0.4 C
1 coulomb = 6.25 × 1018 electron
– 0.4 C = 0.4 × 6.25 × 1018 electrons
= -2.5 × 1018 electrons

Question 2.
Calculate the amount of charge that would flow in 2 hours through an element of an electric bulb drawing a current of 2.5A.
Answer:
Current I = 2.5 A
time t = 2 hours = 2 × 3600 seconds
t = 7200 s
Amount of charge Q = I × t = 2.5 × 7200
Q = 18,000

Samacheer Kalvi 9th Science Guide Chapter 4 Electric Charge and Electric Current

Question 3.
The values of the current (I) flowing through a resistor for various potential differences V across the resistor are given below. What is the value of resistor?
Samacheer Kalvi 9th Science Guide Chapter 4 Electric Charge and Electric Current 1 (2)
[Hint: plot V-I graph and take slope]
Answer:
Samacheer Kalvi 9th Science Guide Chapter 4 Electric Charge and Electric Current 2 (2)

Samacheer Kalvi 9th Science Guide Chapter 4 Electric Charge and Electric Current

Intext Activities

ACTIVITY – 1

Take a condemned electronic circuit board in a TV remote or old mobile phone. Look at the electrical symbols used in the circuit. Find out the meaning of the symbols known to you.
Samacheer Kalvi 9th Science Guide Chapter 4 Electric Charge and Electric Current 3
Samacheer Kalvi 9th Science Guide Chapter 4 Electric Charge and Electric Current 4
[End of the activity]

ACTIVITY – 2
Cut an arrow shaped strip from aluminium foil. Ensure that the head is a fine point. Keep the arrow shaped foil on a wooden board. Connect a thin pin to two lengths of wire. Connect the wires to the terminals of electric cell, may be of 9V. Press one pin onto the pointed tip and the other pin at a point about one or two mm away. Can you see that the tip of aluminum foil starts melting?
Samacheer Kalvi 9th Science Guide Chapter 4 Electric Charge and Electric Current 6

Aim :
To understand the heating effect of electric current.

Materials Required :
Aluminum strip, wooden board, bell pins, cell of 9 V.

Procedure :
Cut an arrow shaped strip from aluminum foil. Keep the arrow shaped foil on a wooden board. Connect a pin to two lengths of wire. Connect the wires to the terminals of electric cell of 9 V. Press one pin onto the pointed tip and another pin at a point about one or two mm away.

Observation :
The tip’of aluminum foil starts melting.

Conclusion :
It starts melting because the electrons while moving in the wire suffer resistance. Work is done to overcome the resistance which is converted into heat energy. This conversion of electrical energy into heating energy is called the heating effect of electric current.

Samacheer Kalvi 9th Science Guide Chapter 4 Electric Charge and Electric Current

ACTIVITY – 3

Take a beaker half filled with copper sulphate solution. Take a carbon rod from a used dry cell. Wind a wire on its upper end. Take a thick copper wire, clean it well and flatten it with a hammer. Immerse both the copper wire and carbon rod in the copper sulphate solution. Connect the carbon rod to the negative terminal of an electric cell and copper wire to the positive terminal of the cell. Also ensure that the copper and the carbon rod do not touch each other, but are close enough. Wait and watch. After some time you would find fine copper deposited over the carbon rod. This is called as electroplating. This is due to the chemical effect of the current.
Samacheer Kalvi 9th Science Guide Chapter 4 Electric Charge and Electric Current 19

Aim:
Electroplating carbon rod with copper.

Materials Required:
Beaker, copper sulphate solution, carbon rod, thick copper wire and hammer.

Procedure :

  • Take a beaker half filled with copper sulphate solution.
  • Take a carbon rod and wind a wire on its upper end.
  • Take a thick copper wire, clean it well and flatten it with a hammer.
  • Immerse both the copper wire and carbon rod in the copper sulphate solution.
  • Connect the carbon rod to the negative terminal of the cell and copper wire to the positive terminal of the cell.
  • Ensure both the rods do not touch each other, but are close enough.
  • Observe for some time.

Observation :
After some time, we would find fine copper deposited over the carbon rod.

Conclusion :
When the current passes through the copper sulphate solution, the copper ions migrate from the copper sulphate solution towards the cathode (-ve terminal). These copper ions get deposited on the carbon rod and form a coating of a fine layer on it.

This process of coating a metal over another metal by electrolysis is called electroplating. This is due to the chemical effect of electric current.

9th Science Guide Electric Charge and Electric Current Additional Important Questions and Answers

I. Choose the correct answer:

Question 1.
A current of 2A passing through the conductor produces 80 J of heat in 10 seconds. The resistance of the conductor is ……………..
(a) 0.5Ω
(b) 2Ω
(c) 4Ω
(d) 20Ω
Answer:
(b) 2Ω

Question 2.
The resistance of a straight conductor is independent of …………………..
(a) temperature
(b) material
(c) cross sectional area
(d) shape of cross section
Answer:
(d) shape of cross section

Question 3.
Two resistances R1 and R2 are connected is parallel. Their equivalent resistance is
Samacheer Kalvi 9th Science Guide Chapter 4 Electric Charge and Electric Current 7
Samacheer Kalvi 9th Science Guide Chapter 4 Electric Charge and Electric Current 8
Answer:
Samacheer Kalvi 9th Science Guide Chapter 4 Electric Charge and Electric Current 20

Question 4.
If in the circuit, power dissipation is 150 W, then R is ……………..
Samacheer Kalvi 9th Science Guide Chapter 4 Electric Charge and Electric Current 9
(a) 2Ω
(b) 6Ω
(c) 5Ω
(d) 4Ω
Answer:
(b) 6Ω

Samacheer Kalvi 9th Science Guide Chapter 4 Electric Charge and Electric Current

Question 5.
The force between two parallel wires carrying currents has been used to define…………..
(a) ampere
(b) coulomb
(c) volt
(d) watt
Answer:
(a) ampere

Question 6.
Electric current passes through a metallic conductor due to the movement of ……………
(a) ions
(b) ampere
(c) electrons
(d) protons
Answer:
(c) electrons

Question 7.
What is the maximum resistance one can make with ten 1Ω resistors?
(a) 1Ω
(b) 2Ω
(c) 5Ω
(d) 10Ω
Answer:
(d) 10Ω

Question 8.
Two conductors of resistance 2 R and R are connected in series in a battery circuit. The ratio of heat developed In them is ……………………
(a) 2 : 1
(b) 1 : 2
(c) 1 : 3
(d) 1 : 4
Ans:
(a) 2 : 11

Samacheer Kalvi 9th Science Guide Chapter 4 Electric Charge and Electric Current

Question 9.
1 volt = …………..
Samacheer Kalvi 9th Science Guide Chapter 4 Electric Charge and Electric Current 10
Samacheer Kalvi 9th Science Guide Chapter 4 Electric Charge and Electric Current 11
Answer:
Samacheer Kalvi 9th Science Guide Chapter 4 Electric Charge and Electric Current 12

Question 10.
The resistance of a conductor is R. If Its length is doubled, then its new resistance will be ……………….
(a) R
(b) 2R
(c) 4R
(d) 8R
Answer:
(C) 4R

Samacheer Kalvi 9th Science Guide Chapter 4 Electric Charge and Electric Current

Question 11.
The following is not a safety device.
(a) Fuse
(b) Trip switch
(c) Ground connection
(d) Wire
Answer:
(d) wirel

Question 12.
In India the frequency of alternating current is,
(a) 220 Hz
(b) 50 Hz
(c) 5 Hz
(d) 100 Hz
Answer:
(b) 50 Hz

Samacheer Kalvi 9th Science Guide Chapter 4 Electric Charge and Electric Current

II. Fill in the blanks:

1. The number of electrons constituting 1-coulomb charge is………………….
Answer:
6.25 × 1018

2. Resistors are connected in series if the resistance of the electric circuit is to be………………….
Answer:
increased

3. Electric fuse is a wire made up of a material having ………………….melting point.
Answer:
low

4. ………………….is the only non-metal that is a good conductor of electricity.
Answer:
Graphite

5. If the area of cross section of the conductor is doubled its resistance gets ………………….
Answer:
halved

Samacheer Kalvi 9th Science Guide Chapter 4 Electric Charge and Electric Current

6. A negative charge will move from …………………. to …………………. potential.
Answer:
lower, higher

7. ………………….is work done per unit charge.
Answer:
Potential difference

Samacheer Kalvi 9th Science Guide Chapter 4 Electric Charge and Electric Current

8. An electrochemical cell converts …………………. energy into …………………. energy.
Answer:
chemical, electrical

9. Three resistors are connected in series with a cell. If the current in each resistor is 1.5A, then the current through the cell will be ………………….. Answer:
1.5A

10. Three resistors are connected in parallel with a battery. If the current in each resistor is 2A, then the current through the battery will be …………………..
Answer:
6A

11. As electrons are revolving in the ………………….of an atom they can be easily removed from an atom and also added to it.
Answer:
orbits

Samacheer Kalvi 9th Science Guide Chapter 4 Electric Charge and Electric Current

12. If an electron is added in excess to an atom then the atom is ………………….charged.
Answer:
negatively

13. The excess of electrons make an object negative and ………………….of electrons make it positive.
Answer:
deficit

14. Electric charge is ………………….in nature.
Answer:
additive

15. Electric lines of force are ………………….lines.
Answer:
imaginary

Samacheer Kalvi 9th Science Guide Chapter 4 Electric Charge and Electric Current

16. For an isolated positive charge the electric lines of force are radial…………………. and for an isolated negative charge they are radial…………………..
Answer:
outwards, inwards

17. ………………….at a point is a measure of force acting on a unit positive charge placed at that point.
Answer:
Electric field

18. Electric potential is a measure of the ………………….on the unit positive charge to bring it to that point against all electrical forces.
Answer:
work done

Samacheer Kalvi 9th Science Guide Chapter 4 Electric Charge and Electric Current

19. The movement of positive charge is called as ………………….
Answer:
conventional current

20. The …………………. is the measure of opposition offered by the component to the flow of electric current through it.
Answer:
resistance

21. The process of conduction of electric current through solution is called………………….
Answer:
electrolysis

22. The device used to convert AC to DC is called………………….
Answer:
rectifier

23. Trip switch is a …………………. safety device.
Answer:
electro mechanical

Samacheer Kalvi 9th Science Guide Chapter 4 Electric Charge and Electric Current

III. True or False:

1. A fuse is used in an electric circuit to stop high current flowing through the circuit.
Answer:
True.

2. Rheostat is also known as fixed resistance.
Answer:
False.
Correct statement: Rheostat is also known as a variable resistance.

3. An ammeter is always placed in parallel with the circuit.
Answer:
False.
Correct statement: An ammeter is always placed in series with the circuit.

4. The resistance of a dry human body is high.
Answer:
True.

Samacheer Kalvi 9th Science Guide Chapter 4 Electric Charge and Electric Current

5. For current to flow, one needs art open circuit.
Answer:
Correct statement: For current to flow, one needs a closed circuit.

6. A comb rubbed with hair and brought near pieces of paper attracts them, because both comb and paper get similarly charged.
Answer:
False.
Correct statement: A comb rubbed with hair and brought near pieces of paper attracts them, because both comb and paper get oppositely charged.

7. Overloading of electric circuits can lead to short-circuiting.
Answer:
True.

Samacheer Kalvi 9th Science Guide Chapter 4 Electric Charge and Electric Current

8. Electrons in outer orbits are called free electrons.
Answer:
True.

9. Electric fuse works on the Joule heating principle.
Answer:
True.

Samacheer Kalvi 9th Science Guide Chapter 4 Electric Charge and Electric Current

IV. Match the following:

I.

Column I Column II
1. Resistor a) Galvanometer
2. Connecting wire b) Voltmeter
3. Current in an electric circuit c) Copper
4. Potential difference d) Constantan

Answer:
1-d, 2-c, 3 -a, 4-b

II.

Column I Column II
1. Electric power a) Volt
2. Electrical energy b) Coulomb
3. Electric charge c) Watt
c) Watt d) Joule

Answer:
1-c, 2-d, 3-c, 4-a

Samacheer Kalvi 9th Science Guide Chapter 4 Electric Charge and Electric Current

V. Assertion and Reason type questions :

Mark the correct choice as :
(a) If both assertion and reason are true and reason is the correct explanation of assertion.
(b) If both assertion and reason are true but reason is not the correct explanation of assertion.
(c) If assertion is true but reason is false.
(d) If assertion is false but reason is true.

Question 1.
Assertion (A): Electric current will not flow between two charged bodies when connected if their charges are the same.
Reason (R): Current is the rate of flow of charge.
Answer:
(d) Assertion is false but the reason is true
Reason: Current will not flow when two bodies are at the same potential. When their charges are the same, their potential may be different. Hence current may flow in this case.

Samacheer Kalvi 9th Science Guide Chapter 4 Electric Charge and Electric Current

Question 2.
Assertion (A) : A bird perches on a high power line and nothing happens to the bird.
Reason (R) : The level of the bird is very high from the ground.
Answer:
(c) Assertion is true but reason is false
Reason: Electric shock is due to the electric current flowing through a living body. When the bird perches on a single high power line, no current passes through its body. Because its body is at an equipotent surface (i.e.) there is no potential difference. While when a man touches the same line, standing bare foot on the ground the electrical circuit is completed through the ground. The hands of man are at high potential and his feet are at low potential. Hence the large amount of current flows through the body of the man and the person, therefore, gets a fatal shock.

VI. Answer in one word:

Question 1.
Name the force which acts between two point charges obey Newton’s third law.
Answer:
Electrostatic force.

Question 2.
What is the SI unit for the current?
Answer:
ampere (A).

Samacheer Kalvi 9th Science Guide Chapter 4 Electric Charge and Electric Current

Question 3.
Name the device which is used to measure the strength of the electric current in an electric circuit.
Answer:
Ammeter.

Question 4.
What is the rate at which charges flow past a point on a circuit?
Answer:
Current.

Question 5.
Name a device that helps to maintain a potential difference across conductors.
Answer:
Cell or battery.

Question 6.
What does the circuit symbol Samacheer Kalvi 9th Science Guide Chapter 4 Electric Charge and Electric Current 13 represent?
Answer:
Wire crossing without touching each other.

Samacheer Kalvi 9th Science Guide Chapter 4 Electric Charge and Electric Current

Question 7.
How many electrons accumulate to make 1C of electric charge?
Answer:
1C = 6.25 × 1018 electrons.

Question 8.
What is the charge of one electron?
Answer:
e= 1.6 × 10-19C.

Question 9.
What is the measure of the work done on the unit positive charge to bring it to that point against all electrical forces?
Answer:
Electric potential

Question 10.
How is a voltmeter connected in the circuit to measure the potential difference between two points?
Answer:
Parallel

Samacheer Kalvi 9th Science Guide Chapter 4 Electric Charge and Electric Current

VII. Subjective Problems:

Question 1.
Calculate the charge passing through a lamp in 2 minutes if the current is 3A.
Solution:
Current I = 3A
Time t = 2 minutes = 120seconds
Charge q = ?
q = I × t = 3 × 120
Charge q = 36.C

Question 2.
Calculate the current in a wire if a charge of 1500 coulomb flows through it in 5 minutes.
Solution:
Charge q = 1500 C
Time t = 5 minutes = 300 seconds
Current I =?
I = q/t = \(\frac{1500}{300}\)
Current I = 5A

Samacheer Kalvi 9th Science Guide Chapter 4 Electric Charge and Electric Current

Question 3.
A charge of 400C flows through a conductor for 13 minutes and 20 seconds. Find the magnitude of the current flowing through the conductor.
Answer:
Q = 400C
t = 13 min and 20s = 13 × 60 + 20
= 780 + 20
= 800s
Current I = \(\frac{Q}{t}=\frac{400}{800}=0.5 \mathrm{A}\)

Question 4.
1020 electrons, each having a charge of 1.6 x 10-19 C, flows in a circuit V is 0.1s. What is the current in ampere?
Solution :
n = 1020 electrons
e = 1.6 × 10-19C
t = 0.1s
Charge q = ne
= 1020 × 1.6 × 10-19
= 16C
Current I = \(\frac{q}{t}=\frac{16}{0.1}=160 \mathrm{~A}\)
∴ Current = 160 A

Samacheer Kalvi 9th Science Guide Chapter 4 Electric Charge and Electric Current

VIII. Long Answer Questions

Question 1.
a State Ohm’s law.
b. Draw a circuit diagram for the verification of ohm’s law. Also, plot graphically the variation of current with a potential difference.
Answer:
a. Ohm’s law states that the current passing through a conductor is directly proportional
to the potential difference a cross its ends, provided the physical conditions like temperature density etc. remain unchanged V ∝ I or V = IR.
b.
Samacheer Kalvi 9th Science Guide Chapter 4 Electric Charge and Electric Current 14

Question 2.
a. Why is series arrangement not used for domestic cricuits?
b. Explain why fuse wire is always connected in series arrangement.
c. Why are copper and aluminium wires useually employed for electricity transmission?
Answer:
a. Series arrangement is not used for domestic circuits because same current will flow through all the appliances. The equivalent resistance will get added and hence the current drawn by the circuit will be less.

b. Fuse wire is always connected in series in a circuit as it has to check the flow of current through the circuit and prevent the extra flow of current through it.

c. Fuse wire is always connected in series in a circuit as it has to check the flow of current through the circuit and prevent the extra flow of current through it.

Samacheer Kalvi 9th Science Guide Chapter 4 Electric Charge and Electric Current

Question 3.
Explain the dangers of electricity and precautions to be taken while handling electricity.
Answer:

  • Damaged insulation – Do not touch the bare wire, use safety gloves, and stand on an insulating stool or rubber slippers while handling electricity.
  • Overheating of cables – use quality ISI certified cable wires for domestic wiring
  • Overload of power sockets – do not connect too many electrical devices to a single electrical socket.
  • Inappropriate use of electrical appliances – always uses the electrical appliances according to the power rating of the device like AC point, TV point, microwave oven point, etc.
  • Environment with moisture and dampness – keep the place where there is electricity out of moisture and wetness as it will lead to leakage of electric current.
  • Beyond the reach of children – the electrical sockets are to be kept away from the reach of little children who do not know the dangers of electricity.

Question 4.
Write the difference between resistance in series and in parallel.
Answer:
Samacheer Kalvi 9th Science Guide Chapter 4 Electric Charge and Electric Current 15

Samacheer Kalvi 9th Science Guide Chapter 4 Electric Charge and Electric Current

IX.

Question 1.
Distinguish e.m.f and potential difference.
Answer:
As both e.m.f and potential difference are measured in volt, they may appear the same. But they are not. The e.m.f refers to the voltage developed across the terminals of an electrical source when it does not produce current in the circuit. Potential difference refers to the voltage developed between any two points (even across electrical devices) in an electric circuit when there is current in the circuit.

Question 2.
Some common symbols in the electrical circuit.
Answer:
Samacheer Kalvi 9th Science Guide Chapter 4 Electric Charge and Electric Current 16

Question 3.
Write a note on direct current.
Answer:

  • Current in electrical circuits is due to the motion of positive charge from higher potential to lower potential or electron from lower to higher electrical potential.
  • Electrons move from negative terminal of the battery to positive of the battery. Battery is used to maintain a potential difference between the two ends of the wire.
  • Battery is one of the sources for dc current. The dc is due to the unidirectional flow of electric charges. Some other sources of dc are solar cells, thermocouples etc. The graph depicting the direct current is shown in Figure.
    Samacheer Kalvi 9th Science Guide Chapter 4 Electric Charge and Electric Current 17
  • Many electronic circuits use dc. Some examples of devices which work on dc are cell phones, radio, electric keyboard, electric vehicles etc.

Samacheer Kalvi 9th Science Guide Chapter 4 Electric Charge and Electric Current

Question 4.
Write a note on alternating current.
Answer:

  • If the direction of the current in a resistor or in any other element changes its direction alternately, the current is called an alternating current.
  • The alternating current varies sinusoidally with time. This variation is characterised by a term called as frequency.
  • Frequency is the number of complete cycle of variation, gone through by the ac in
    one second. s
  • In ac, the electrons do not flow in one direction because the potential of the terminals vary between high and low alternately.
  • Thus, the electrons move to and fro in the wire carrying alternating current. It is diagrammatically represented in Figure

Samacheer Kalvi 9th Science Guide Chapter 4 Electric Charge and Electric Current 18

Samacheer Kalvi 9th Science Guide Chapter 4 Electric Charge and Electric Current

Question 5.
Explain the advantages of Ac over Dc.
Answer:

  • The voltage of ac can be varied easily using a device called transformer. The ac can be carried over long distances using step-up transformers.
  • The loss of energy while distributing current in the form of ac is negligible. Direct current cannot be transmitted as such.
  • The ac can be easily converted into dc and generating ac is easier than dc
  • The ac can produce electromagnetic induction which is useful in several ways.

X. Define the following:

1. Electric force: The force existing between the charges is called an ‘electric force’.
2. Electric potential: Electric potential is a measure of the work done on the unit positive charge to bring it to that point against all electrical forces.
3. Conventional current and electron current: The movement of the positive charge is called as ‘conventional current’. The flow of electrons is termed as ‘electron current’.
4. Current: Current is the rate at which charges flow past a point on a circuit.
5. Electromotive force (e.m.f.): The e.m.f of an electrical energy source is one volt if one joule of work is done by the source to drive one coulomb of charge completely around the circuit.
6. One ohm: One ohm is the resistance of a component when the potential difference of one volt applied across the component drives a current of one ampere through it.
7. Fixed resistor: A fixed resistor has a resistance of a fixed value. Common types of fixed resistors include carbon film resistors and wire-wound resistors.
8. Variable resistor: A variable resistor has a resistance that can be varied. It is used to vary the amount of current flowing in a circuit.
9. Electrolysis and electrolyte: The process of conduction of electric current through solutions is called ‘electrolysis’. The solution through which the electricity passes is called ‘electrolyte’.
10. Synaptic signals: Extremely weak electric current is produced in the human body by the movement of charged particles. These are called synaptic signals. These signals are produced by the electrochemical process. They travel between the brain and the organs through the nervous system.
11. Magnetic effect of current: A wire or a conductor carrying current develops a magnetic field perpendicular to the direction of the flow of current. This is called the magnetic effect of current.
12. Frequency: Frequency is the number of the complete cycle of variations, gone through by the ac in one second.
13. Rectifier: The device used to convert ac to dc is called a rectifier.
14. Resistance: The measure of opposition offered by the component to the flow of electric current through it.
15. Resistors: The components used for providing resistance are called resistors.

Samacheer Kalvi 9th Science Guide Chapter 3 Fluids

Tamilnadu State Board New Syllabus Samacheer Kalvi 9th Science Guide Pdf Chapter 3 Fluids Text Book Back Questions and Answers, Notes.

Tamilnadu Samacheer Kalvi 9th Science Solutions Chapter 3 Fluids

9th Science Guide Fluids Text Book Back Questions and Answers

I. Choose the correct answer:

Question 1.
The size of an air bubble rising up in the water
(a) decreases
(b) increases
(c) remains the same
(d) may increase or decrease
Answer:
(b) increases

Samacheer Kalvi 9th Science Guide Chapter 3 Fluids

Question 2.
Clouds float in the atmosphere because of their low
(a) density
(b) pressure
(c) velocity
(d) mass
Answer:
(a) density

Question 3.
In a pressure cooker, the food is cooked faster because
(a) increased pressure lowers the boiling point.
(b) increased pressure raises the boiling point.
(c) decreased pressure raises the boiling point.
(d) increased pressure lowers the melting point.
Answer:
(b) increased pressure raises the boiling point

Question 4.
An empty plastic bottle closed with an airtight stopper is pushed down into a bucket filled with water. As the bottle is pushed down, there is an increasing force on the bottom. This is because
(a) more volume of liquid is displaced.
(b) more weight of liquid is displaced.
(c) pressure increases with depth.
(d) All the above.
Answer:
(c) pressure increases with depth

Samacheer Kalvi 9th Science Guide Chapter 3 Fluids

II. Fill in the blanks :

1. The weight of the body immersed in a liquid appears to be ………………… than its actual weight
Answer:
less

2. The instrument used to measure atmospheric pressure is …………
Answer:
Barometer

3. The magnitude of buoyant force acting on an object immersed in a liquid depends on ……………. of the liquid.
Answer:
density

4. A drinking straw works on the existence of ……………….
Answer:
atmospheric pressure

Samacheer Kalvi 9th Science Guide Chapter 3 Fluids

III. State whether true or false. If false, correct the statement:

1. The weight of fluid displaced determines the buoyant force on an object.
Answer:
True.

2. The shape of an object helps to determine whether the object will float or not.
Answer:
False.
Correct statement: The density of an object helps to determine whether the object will floater sink.

Samacheer Kalvi 9th Science Guide Chapter 3 Fluids

3. The foundations of high-rise buildings are kept wide so that they may exert more pressure on the ground.
Answer:
False.
Correct statement: They may exert less pressure on the ground.

4. Archimedes’ principle can also be applied to gases.
Answer:
True.

5. Hydraulic press is used in the extraction of oil from oilseeds.
Answer:
True.

IV. Match the following :

Density hpg
1 gwt  Milk
Pascal’s law  Pressure
Pressure exerted by a fluid Mass/Volume
Lactometer 980 dyne

Answer:

Density Mass/Volume
1 gwt 980 dyne
Pascal’s law  Pressure
Pressure exerted by a fluid hpg
Lactometer  Milk

V. Answer in brief :

Question 1.
On what factors the pressure exerted by the liquid depends on?
Answer:
The pressure exerted by the liquid depends on the

  • Depth
  • Density of the liquid
  • Acceleration due to gravity.

Question 2.
Why does a helium balloon float in the air?
Answer:
Helium is much less dense than ordinary air which gives them buoyancy and thus floats in the air.

Samacheer Kalvi 9th Science Guide Chapter 3 Fluids

Question 3.
Why it is easy to swim in river water than in seawater?
Answer:
The question itself is wrong. It is easier to swim in seawater than in the river water. It is because seawater has
(i) greater density and
(ii) larger buoyant force than river water.

Question 4.
What is meant by atmospheric pressure?
Answer:
The pressure exerted by the atmospheric gases on its surroundings and on the surface of the earth is called atmospheric pressure.

Question 5.
State Pascal’s law.
Answer:
Pascal’s law: The external pressure applied to an incompressible liquid is transmitted uniformly throughout the liquid.

Samacheer Kalvi 9th Science Guide Chapter 3 Fluids

VI. Answer in detail:

Question 1.
An appropriate illustration proves that the force acting on a smaller area exerts a greater pressure.
Answer:
Consider standing on loose sand. Your feet go deep into the sand. Now, when you lie down on the sand, you will find that your body will not go that deep into the sand. In both cases, the force exerted on the sand is the weight of your body which is the same. This force acting perpendicular to the surface is called thrust. When you stand on loose sand, the force is acting on an area equal to the area of your feet.

When you lie down, the same force acts on an area of your whole body, which is larger than the area of your feet. Therefore the effect of thrust, that is, the pressure depends on the area on which it acts. The effect of thrust on sand is larger while ‘ standing than lying.

Question 2.
Describe the construction and working of the mercury barometer.
Answer:
Samacheer Kalvi 9th Science Guide Chapter 3 Fluids 1

Mercury Barometer
1. It is designed by Torricelli.

Construction :
2. Mercury Barometer consists of long glass tube closed at one end and opened at the other.
3. Mercury filled through open end and close that end by thumb and open it after immersing it into a trough of mercury.

Working:
4. The Barometer works by balancing the mercury in the glass tube against the outside air pressure.
5. If air pressure increases, it pushes more of the mercury up into the tub.
6. If air pressure decreases, more mercury drains from the tub.
7. As vacuum cannot exert pressure, Mercury in the tube provides a precise measure of air pressure which is called atmospheric pressure.
8. It is used in a laboratory or weather station.

Samacheer Kalvi 9th Science Guide Chapter 3 Fluids

Question 3.
How does an object’s density determine whether the object will sink or float in water?
Answer:
Whether an object will sink or float in a liquid is determined by the density of the object compared to the density of the liquid. If the density of a substance is less than the density of the liquid it will float. For example, a piece of wood which is less dense than water will float on it. Any substance having more density than water (for example, a stone), will sink into the water.

Question 4.
Explain the construction and working of a hydrometer with a diagram.
Answer:
Samacheer Kalvi 9th Science Guide Chapter 3 Fluids 2
Purpose:
To measure density (or) relative density of the liquid.

Samacheer Kalvi 9th Science Guide Chapter 3 Fluids

Principle :
The weight of the liquid displaced by the immersed portion of the hydrometer is equal to the weight of the hydrometer. [Flotation principle].

Construction
Lower end of hydrometer :
A cylindrical stem having a spherical bulb which partially W Lead shots
filled with lead shots or mercury which helps to float or stand vertical in liquids.

Upper end of hydrometer:
A narrow tube has markings so that the relative density of liquids can be read off directly.

Working:

  1. Liquid to be tested is poured into the glass jar.
  2. The hydrometer is gently lowered into the liquid until it floats freely.
  3. The reading against the level touching the tube gives the relative density of the liquid.

Question 5.
State the laws of flotation.
Answer:
Laws of flotation are

  • The weight of a floating body in a fluid is equal to the weight of the fluid displaced by the body.
  • The centre of gravity of the floating body and the centre of buoyancy are in the same vertical line.

Samacheer Kalvi 9th Science Guide Chapter 3 Fluids

VII. Assertion and Reason :

Mark the correct answer is:
(a) If both assertion and reason are true and reason is the correct explanation of assertion.
(b) If both assertion and reason are true but reason is not the correct explanation of assertion.
(c ) If assertion is true but reason is false.
(d) If assertion is false but reason is true.

Question 1.
Assertion (A) : To float, body must displace liquid whose weight is equal to the actual weight.
Reason (R): The body will experience no net downward force in that case.
Answer:
(a) Both assertion and reason are true and reason is the correct explanation of assertion]

Question 2.
Assertion (A) : Pascal’s law is the working principle of a hydraulic lift.
Reason (R): Pressure is thrust per unit area.
Answer:
(b) Both assertion and reason are true but reason is not the correct explanation of assertion.]
Reason : Pascal’s law is the working principle of Hydraulic lift. In Hydraulic lift, applied pressure is transmitted uniformly and multiplied throughout the system.

VIII. Numerical Problems :

Question 1.
A block of wood of weight 200 g floats on the surface of water. If the volume of the block is 300 cm3, calculate the upthrust due to water.
Answer:
Weight of woodblock, m = 200 g
Volume of the woodblock, V = 300cm3
Upthrust = Weight of the fluid displaced = Volume of the woodblock
Upthrust = 300 cm3

Samacheer Kalvi 9th Science Guide Chapter 3 Fluids

Question 2.
Density of mercury is 13600 kg m-3. Calculate the relative density.
Answer:
Density of Mercury = 13600 kg m-3
Density of water at 4°C= 1000 kg m-3
Samacheer Kalvi 9th Science Guide Chapter 3 Fluids 3

Question 3.
The density of water is 1 g cm-3. What is its density in S.I. units?
Answer:
Density of water in SI units = 1000 kg / m3

Question 4.
Calculate the apparent weight of wood floating on water if it weighs 100g in air.
Answer:
Mass of wood = 100 g.
As the wood floats on the water, water will not be displaced.
So, the actual weight of wood is equal to the Apparent weight of wood.

IX. Higher Order Thinking Skills :

Question 1.
How high does the mercury barometer stand on a day when atmospheric pressure is 98.6 kPa?
Answer:
Pressure of Atmosphere PatnT = 98.6 kPa.
Density of Mercury, ρHg = 13.6 × 103 kg/cm3
Acceleration due to gravity, g = 9.8 m/s2
Samacheer Kalvi 9th Science Guide Chapter 3 Fluids 4

Samacheer Kalvi 9th Science Guide Chapter 3 Fluids

Question 2.
How does a fish manage to rise up and move down in the water?
Answer:

  • Fish manages to rise up in the water by reducing its density by filling oxygen in the bladder via the gills. Thus volume will be increased to support its ascending motion.
  • Fish moves down by decreasing its volume by releasing oxygen from the bladder. Thus volume will be decreased so it will sink in the water.

Question 3.
If you put one ice cube in a glass of water and another in a glass of alcohol, what would you observe? Explain your observations.
Answer:
Ice cube in water: As the density of ice cube is less than water, the ice cube floats in water.
Ice cube in alcohol: As the density of the ice cube is greater than alcohol, the ice cube will sink in alcohol.
Note: Density : Water = 1.00, Ice cube = 0.917, Alcohol = 0.78

Question 4.
Why does a boat with a hole in the bottom would eventually sink?
Answer:
A boat with a hole in the bottom eventually sinks due to :

  • The water entered through a hole will increase the weight of the boat.
  • The boat becomes heavier so it cannot displace more water. So the boat sinks.

Samacheer Kalvi 9th Science Guide Chapter 3 Fluids

Intex activities

ACTIVITY – 1

Stand on the loose stand. Your feet go deep into the sand. Now, lie down on the sand. What happens? You will find that your body will not go that deep into the sand. Why?

Aim:
To demonstrate the effect of thrust

Materials Required:
Sand

Procedure:

    1. First, you stand on the sand on your feet.
    2. Lie down on the sand with your whole body.

Observation:

  1. While standing on your feet on sand, your feet go deep into the sand.
  2. While lying down with your body on the sand, your body will not go deep into the sand.

Conclusion:

  1. Pressure depends upon the area on which it acts.
  2. The effect of thrust on sand is larger while standing than lying.

Samacheer Kalvi 9th Science Guide Chapter 3 Fluids

ACTIVITY – 2

Take a transparent plastic pipe. Also, take a balloon and tie it tightly over one end of the plastic pipe. Pour some water in the pipe from the top. What happens? The balloon tied at the bottom stretches and bulges out. It shows that the water poured in the pipe exerts pressure on the bottom of its container.
Samacheer Kalvi 9th Science Guide Chapter 3 Fluids 5
Aim: To demonstrate that water exerts pressure on the bottom of the container.

Materials Required: Plastic pipe, Balloon, Water.

Procedure :

  1. Take a transparent plastic pipe and a balloon.
  2. Tie the balloon tightly over one end of the plastic pipe.
  3. Keep the pipe with the closed end at the bottom.
  4. Pour some water in the pipe from the top.

Observation: The balloon tied at the bottom stretches and bulges out.

Conclusion: Water poured in the pipe exerts pressure on the bottom of its container.

[End of the activity]

Samacheer Kalvi 9th Science Guide Chapter 3 Fluids

ACTIVITY-3

Take a large plastic can. Punch holes with a nail in a vertical line on the side of the can as shown in the figure. Then fill the can with water. The water may just dribble out from the top hole, but with the increased speed at the bottom holes as depth causes the water to squirt out with more pressure.
Samacheer Kalvi 9th Science Guide Chapter 3 Fluids 6
Aim:
To demonstrate that pressure increases as depth increases.

Materials Required:

  1. Large plastic can.
  2. A sharp nail.

Procedure :

  1. Take a large plastic can.
  2. Punch holes with a nail in a vertical line up on the side of the can every inch or several centimeters.

Observation:

  1. Water dribbles out from the top hole.
  2. Water from the bottom hole flows with increased speed.

Conclusion:
Depth causes water to squirt out with more pressure.

Samacheer Kalvi 9th Science Guide Chapter 3 Fluids

ACTIVITY – 4

Take two liquids of different densities say water and oil to the same level in two plastic containers. Make holes in the two containers at the same level. What do you see? It can be seen that water is squirting out with more pressure than oil. This indicates that pressure depends on density of the liquid.
Samacheer Kalvi 9th Science Guide Chapter 3 Fluids 7

Aim :
To demonstrate pressure depends on the density of the liquid.

Materials Required:

  1. Two plastic containers
  2. Water
  3. Oil (Both same volume)
  4. Sharp nail

Procedure:

  1. Take water and oil to the same level in two plastic containers.
  2. Make a hole at the same level in two containers.

Observation:
Water squirts out with more pressure than that of oil.

Conclusion:
Pressure depends on the density of the liquid.

Samacheer Kalvi 9th Science Guide Chapter 3 Fluids

ACTIVITY – 5

Take two identical flasks and fill one flask with water to the 250 cm3 mark and the other with kerosene to the same 250 cm3 mark. Measure them in a balance. The flask filled with water will be heavier than the one filled with kerosene. Why? The answer is in finding the mass per unit volume of kerosene and water in respective flasks.
Samacheer Kalvi 9th Science Guide Chapter 3 Fluids 8
Aim :
To prove that the density of a substance is the mass per unit volume of a given substance.

Materials Required:

  1. Two identical flasks.
  2. Water
  3. Kerosene (same volume as water)

Procedure :

  1. Take two identical flasks.
  2. Fill one flask with water to 250 cm3 mark.
  3. Fill the other flask with kerosene to the same 250 cm3 mark.
  4. Measure both flasks in balance separately.

Observation :
The flask filled with water will be heavier than that of the flask filled with kerosene.

Conclusion :

  1. In the above activity, we know that Both water and kerosene have same volume (i.e.) 250 cm3.
  2. The density of the water lg / cm3 and density of kerosene is 0.8g / cm3 mass
  3. Density = \(\frac{\text { mass }}{\text { volume }}\), therefore mass = Density x volume
    Hence mass of water = 1g/cm3 x 250 cm3 = 250g
    mass of kerosene = 0.8 g / cm3 x 250 cm3 = 200g
  4. Even though, water and kerosene have same volume, they have different densities. So water and kerosene have different masses.
  5. Water has more mass than kerosene.
    Hence, we proved that the density of the substance is the mass per unit volume of the substance. [End of the activity]

Samacheer Kalvi 9th Science Guide Chapter 3 Fluids

9th Science Guide Fluids Additional Important Questions and Answers

I. Choose the correct answer :

Question 1.
Intermolecular forces are stronger in ………………
(a) gases
(b) liquids
(c) solids
(d) all the above
Answer:
(c) solids

Samacheer Kalvi 9th Science Guide Chapter 3 Fluids

Question 2.
Water (or) liquids exert pressure on
(a) Upward direction
(b) Downward direction
(c) Lateral direction
(d) All the above
Answer:
(d) All the above

Question 3.
The pressure does not depend upon
(a) Depth
(b) Area
(c) Density
(d) Acceleration due to gravity
Answer:
(b) Area

Question 4.
Fluids in general are
(a) Gases
(b) liquids
(c) Gases or Liquids
(d) None of these
Answer:
(c) Gases or Liquids

Samacheer Kalvi 9th Science Guide Chapter 3 Fluids

Question 5.
Scuba divers wear special suits to withstand
(a) Low pressure
(b) High pressure
(c) Low temperature
(d) High temperature
Answer:
(b) High pressure

Question 6.
To find out relative density of the substance, with respect to density of water……………C is taken.
(a) 4°
(b) 0°
(c) 100°
(d) 60°
Answer:
(a) 4°

Question 7.
Density Bottle is also called as
(a) Saccharometer
(b) Lactometer
(c) Pycnometer
(d) Barometer
Answer:
(c) Pycnometer

Samacheer Kalvi 9th Science Guide Chapter 3 Fluids

Question 8.
An object completely immersed in fluid displaces its own volume of fluid.
(a) Floatation principle
(b) Principle of buoyancy
(c) Pascal’s law
(d) Archimedes principle
Answer:
(d) Archimedes principle

Question 9.
A solid floats in liquid with a portion of it being submerged. Then
(a) The liquid exerts an upthrust equal to weight of the solid
(b) The weight of the dispersed liquid is equal to the weight of solid
(c) Solid exerts a force equal to its weight on liquid
Choose correct statements
(A) a & b
(B) a & c
(C) b & c
(D) All of these
Answer:
(A) a & b

Question 10.
The principle of “Hydrostatic balance” was devised by
(a) Torricelli
(b) Pascal
(c) Archimedes
(d) Newton
Answer:
(c) Archimedes

Samacheer Kalvi 9th Science Guide Chapter 3 Fluids

Question 11.
Saccharometer is used to measure the density of …………….in a liquid.
(a) Milk
(b) Sugar
(c) Alcohol
(d) Ether
Answer:
(b) Sugar

Question 12.
Most buoyant objects are those with relatively
(a) high volume
(b) higher mass
(c) low density
(d) less viscosity
(A) a & b (B) a & c (C) b & c (D) b&d
Answer:
(B) a & c

Question 13.
If there were no gravity, which of the following will not be there for fluid? (HOTS)
(a) Viscosity
(b) Density
(c) Pressure
(d) upthrust
Answer:
(d) upthrust

Samacheer Kalvi 9th Science Guide Chapter 3 Fluids

Question 14.
Human lung is well adopted to breath at a pressure of ………….kPa.
(a) 106.7
(b) 101.3
(c) 98.4
(d) 33.7
Answer:
(b) 101.3

Question 15.
Petroleum-based products float on the surface of the water. This is due to their low ………….
(a) volume
(b) density
(c) specific gravity
(d) viscosity
(A) a & b (B) a & c (C) a & d (D) b & c
Answer:
(D) b & c

Samacheer Kalvi 9th Science Guide Chapter 3 Fluids

II. Fill in the blanks :

1. It is easy to compress a gas whereas liquids are ………………….
Answer:
Incompressible

2. The net force in a particular direction is called ………………….
Answer:
Thrust

3. All flowing substances, both liquids, and gases are called ………………….
Answer:
Fluids

Samacheer Kalvi 9th Science Guide Chapter 3 Fluids

4. The air pressure at sea level is referred as ………………….
Answer:
Atmospheric pressure

5. The pressure in mines is ………………….than sea level.
Answer:
Greater

6. ………………….is the instrument used to measure the atmospheric pressure.
Answer:
Barometer

7. On each lm2 of surface, the force acting is ………………….
Answer:
1.013 kN

8. ………………….is a device for measuring atmospheric pressure without the use of liquids.
Answer:
Aneroid Barometer

Samacheer Kalvi 9th Science Guide Chapter 3 Fluids

9. Absolute Pressure is zero-referenced against a ………………….
Answer:
Perfect Vaccum

10. Psi stands for ………………….
Answer:
Pascal per inch

11. A tyre pressure of 30psi is almost ………………….the atmospheric pressure.
Answer:
Twice

12. The density of the substance is the …………………. of a given substance.
Answer:
mass per unit volume

13. Hydrometer is based on the principle of ………………….
Answer:
Flotation

14. The upward force that is caused due to the pressure difference in liquid (or fluid) is called ………………….
Answer:
Buoyant force

Samacheer Kalvi 9th Science Guide Chapter 3 Fluids

15. Hot air is ………………….dense than ordinary air.
Answer:
less

16. The Lactometer works on the principle of ………………….of milk.
Answer:
gravity

17. Icebergs and ships stay afloat due to ………………….
Answer:
Buoyancy

18. Archimedes principle is the consequence of ………………….
Answer:
Pascal’s law

19. The point in which the force of buoyancy is supposed to act is known as …………………..
Answer:
Centre of buoyancy

20. The centre of gravity of the floating body and the centre of buoyance are in the same ………………….line.
Answer:
Vertical

Samacheer Kalvi 9th Science Guide Chapter 3 Fluids

21. In a fluid, buoyant force exists because the pressure at the ………………….of an object is greater than the pressure at the top.
Answer:
bottom

III. Match the following :

(I)

1. Lactometer a) Relative density
2. Saccharometer b) Alcohol
3. Alcoholometer c) Sugar
4. Pyncometer d) Milk

Answer:
1. d
2. c
3. b
4. a

Samacheer Kalvi 9th Science Guide Chapter 3 Fluids

(II)

1.Hydraulic press a) Archimedes
2.Cartesian Diver b) Floatation
3. Hydrostatic Balance c) Pascal’s law
4. Hydrometer d) Buoyancy

Answer:
1. c
2. d
3. a
4. b

IV. State whether true or false. If false, correct the statement:

1. The shape and size of the solids do not easily change.
Answer:
True.

2. Liquid exerts pressure in the upward direction.
Answer:
False.
Correct statement: Liquid exerts pressure in all directions.

Samacheer Kalvi 9th Science Guide Chapter 3 Fluids

3. The barometer works by balancing the Mercury in the glass tube along with the outside air pressure.
Answer:
False.
Correct statement: The barometer works by balancing the Mercury in the glass tube against the outside air pressure.

4. The absolute pressure is zero-referenced against atmospheric pressure.
Answer:
False.

Correct statement: The absolute pressure is zero-referenced against a perfect vacuum.

5. The external pressure applied on an incompressible liquid is transmitted uniformly throughout the liquid.
Answer:
True.

6. The correct lactometer reading is only obtained at a temperature of 60° C.
Answer:
True.

Samacheer Kalvi 9th Science Guide Chapter 3 Fluids

7. If the buoyant force is less, the object will float.
Answer:
False.
Correct statement: If the buoyant force is less, the object will sink.

8. If the volume of object is above the water surface, then the object is less densed.
Answer:
True.

9. Upthrust = weight of the fluid displaced – apparent weight of the object.
Answer:
False.
Correct statement: Upthrust = Weight of the fluid displaced – apparent loss of weight of the object.

10. Salt water provides less buoyant force than freshwater.
Answer:
False.
Correct statement: Salt water provides more buoyant force than freshwater.

Samacheer Kalvi 9th Science Guide Chapter 3 Fluids

V. Very Short Answer Questions :

Question 1.
Differentiate Liquid from Gas.
Answer:
It is easy to compress a Gas. The liquid is Incompressible.

Question 2.
What is the SI unit of pressure?
Answer:
Newton per squaremeter (Nm-2).

Question 3.
What are factors determining liquid pressure?
Answer:
(i) Depth (b) (ii) Density bf Liquid (□) (iii) Acceleration due to gravity (g).

Question 4.
Write the equation for pressure due to liquid column.
Answer:
P = hg ; P – Pressure, h- depth, p- density, g – Acceleration due to gravity.

Samacheer Kalvi 9th Science Guide Chapter 3 Fluids

Question 5.
What is referred to as atmospheric pressure?
Answer:
Air pressure at sea level is referred to as atmospheric pressure.

Question 6.
Expand the abbreviation ‘psi’.
Answer:
Psi = Pascal per inch.

Question 7.
What are Force multipliers?
Answer:
Hydraulic systems are known as-force multipliers.

Question 8.
Write the SI unit & symbol for density?
Answer:
SI unit = kilogram per meter cube (kg / m3).
Symbol = rho (ρ).

Samacheer Kalvi 9th Science Guide Chapter 3 Fluids

Question 9.
Where do we use lactometers?
Answer:
In milk processing units and Dairies.

VI. Answer in brief :

Question 1.
What happens when pressure is increased in solids?
Answer:
If the pressure is increased in solids

  • it experiences tension
  • it ultimately deforms (or) breaks.

Samacheer Kalvi 9th Science Guide Chapter 3 Fluids

Question 2.
How will you calculate fluid pressure?
Answer:
Samacheer Kalvi 9th Science Guide Chapter 3 Fluids 9

Question 3.
How will you find the absolute pressure?
Answer:

  1. For pressures higher than atmospheric pressure:
    Absolute pressure = Atmospheric pressure + Gauge pressure.
  2. For pressures lower than atmospheric pressure:
    Absolute pressure = Atmospheric pressure – Gauge pressure.

Samacheer Kalvi 9th Science Guide Chapter 3 Fluids

Question 4.
Why do Scuba divers wear special suits and equipment?
Answer:

  1. Deep-sea has pressure twice that of atmospheric pressure.
  2. At high pressure, parts of our body including blood vessels & soft tissues cannot withstand it.
    Hence they use special suits & equipment for protection.

Question 5.
Define Relative Density.
Answer:
Relative density of a substance is defined as ratio of density of substance to density of water at 4°C.
Samacheer Kalvi 9th Science Guide Chapter 3 Fluids 10

Question 6.
Name different types of Hydrometers with their applications.
Answer:

Name of Hydrometer Application (measuring)
1. Lactometer Density of milk
2. Saccharometer Density of sugar in a liquid
3. Alcoholometer Higher levels of alcohols in Spirits

Question 7.
What do you understand by the term “Buoyancy”.
Answer:
When a body partially or completely immersed in a liquid (fluid), the pressure is more at the bottom and less at the surface in the liquid.
This Pressure difference causes an upward force called “Buoyant force”. The phenomenon is called ‘Buoyancy’.

Samacheer Kalvi 9th Science Guide Chapter 3 Fluids

Question 8.
How do submarines sink and float in water?
Answer:
Submarines change the level of floating by pumping in and pumping out water into its compartments.

Question 9.
Differentiate positive & negative buoyant.
Answer:
Positive Buoyant

  1. Weight of the object is less than the amount of water displaced.
  2. More buoyant force
  3. Object will float

Negative Buoyant :

  1. Weight of the object is more than the amount of water displaced.
  2. Less Buoyant force.
  3. Object will sink.

Samacheer Kalvi 9th Science Guide Chapter 3 Fluids

Question 10.
You have a bag of cotton and an iron bar, each indicating a mass of 100 kg when measured on a weighing machine. In reality, one is heavier than the other. Can you say which one is heavier and why?
Answer:
The bag containing the iron bar is heavier than cotton.
Reason: Although both of them have the same weight, the bag of the iron bar has less volume so more dense compared to the bag of cotton which has more volume and less dense.

VII. Answer in detail :

Question 1.
Derive an expression for Pressure due to the Liquid column.
Answer:
A tall beaker filled with water to form a liquid column
Area of the cross-section at bottom = A
Height of liquid column = h
The density of the liquid = ρ
Thrust at bottom of liquid column (F) = Weight of liquid.
F = mg …(1) (∵ m – mass of liquid)
Mass,m = ρ × V ……………… (2)
Volume of liquid columñ, V = Area of cross-section (A) × height (h)
V = Ah ………….(3)
Substitute (3) in (2) n, = ρ Ah ………………… (4)
Substitute (4) in (1) F = ρ Ahg ……………….(5)
Pressure (P) = \(\frac{\text { Thrust (F) }}{\text { Area (A) }}=\frac{\rho \text { A h g }}{\mathrm{A}}\)
∴ P = hpg – This is the expression for pressure due to the liquid column.

Samacheer Kalvi 9th Science Guide Chapter 3 Fluids

Question 2.
Describe the construction and working of the Pycnometer.
Answer:
Pycnometer (Density Bottle)

Purpose: To measure relative density.

Construction :

  1. Pycnometer consists of a ground glass stopper with a fine hole through it.
  2. When the bottle is filled and the stopper is inserted, the excess liquid rises through the hole and runs down outside the bottle.

Working:

  1. The bottle will always contain the same volume of liquid at a constant temperature.
  2. The density of the given volume of substance to the density of equal volume of referred substance is called relative density or specific gravity of the substance.

Question 3.
Explain the Archimedes principle with an example.
Answer:
Principle:
A body immersed in a fluid experiences a vertical upward buoyant force equal to the fluid it displaces.
Samacheer Kalvi 9th Science Guide Chapter 3 Fluids 11

Samacheer Kalvi 9th Science Guide Chapter 3 Fluids

Explanation:
(1) When a body is partially or completely immersed in a fluid at rest, it experiences an upthrust which is equal to the weight of the fluid displaced by it.

(2) Due to the upthrust, the body loses a part of its weight equal to upthrust.
Upthrust = Weight of the fluid displaced.
= Apparent loss of weight of the body.
Apparent weight of an object = True weight of object in air – upthrust.

Question 4.
Describe the purpose, principle and working of Lactometer.
Answer:
Purpose: Lactometer is an instrument to check the purity of milk.
Principle: Gravity of milk.

Construction :

  1. Lactometer consists of a long graduated test tube with a cylindrical bulb.
  2. The cylindrical bulb has graduation from 15 at the top and 45 at the bottom, which filled with mercury.
  3. The test tube is filled with water.
  4. The air chamber causes the instrument to float.
  5. Mercury causes lactometer to sink up proper level and to float in an upright position in the milk.
  6. There is a thermometer inside the lactometer that extends to the upper part of test tube.

Working:

  1. The correct lactometer reading is only obtained at 60°C.
  2. Lactometer measures the cream (density) content of milk.
  3. Lactometer floats in milk if milk has more cream content.
  4. The average reading of normal milk is 32.

Samacheer Kalvi 9th Science Guide Chapter 3 Fluids

VIII. Numerical Problems :

Question 1.
A vessel with water is placed on a weighing pan and it reads 600 g. Now a ball of mass 40 g and density is 0.80g / cm3 is sunk into the water with a pin of negligible volume as shown in the figure. The weighing pan will show the reading of …………….?
Samacheer Kalvi 9th Science Guide Chapter 3 Fluids 12
Solution :
Weight of vessel with water = 600g
Mass of ball = 40g
Density of bal = 0.80 g / cm3
Volume of the ball = \(\frac{\text { mass }}{\text { density }}=\frac{40}{0.80}\)= 50g
So, weight of vessel + volume of ball = 600 + 50 g
The weighing pan will show = 650g
The weighing pan will show = 650g
The reading of a spring balance when a block is suspended from it in air is 60 newton. This reading is changed to 40 newton when the block is submerged in water. Calculate the specific gravity of block.
60 – 40 = 20 newton Weight of block in air
Loss of weight in water 60-newton / 20 newton = 3

Samacheer Kalvi 9th Science Guide Chapter 3 Fluids

Question 2.
The reading of a spring balance when a block is suspended from it in air is 60 newton. This reading is changed to 40 newtons when the block ¡s submerged in water. Calculate the specific gravity of block.
Solution:
Weight of block in air = 60 newton
Loss of weight of block in water = 60 – 40 = 20 newton
Samacheer Kalvi 9th Science Guide Chapter 3 Fluids 13
The specific gravity of block = 3

Question 3.
The mass of a body ¡s 4 kg and its volume is 500 cm3. Find its relative density.
Solution:
Massofthebodym = 4kg = 4000g
Volume ofthebodyv = 500 cm3
Samacheer Kalvi 9th Science Guide Chapter 3 Fluids 14

Samacheer Kalvi 9th Science Guide Chapter 3 Fluids

Question 4.
Calculate the pressure produced by a force of 800 N acting on an area of 2.0 m2
Solution :
Force = 800 N
Area = 2.0m2
Pressure, P =\(\frac{\text { Force }}{\text { Area }}=\frac{800}{2.0}\) = 400 Nm-2
Pressure P = 400 Nm-2 (or) 400 Pa

Question 5.
A swimming pool of width 9.0 m and length 24.0 m is filled with water of depth 3.0 m. Calculate the pressure on the bottom of the pool due to the water.
Solution:
Width of the pool, b = 9.0 m
Length of the pool, h = 24.0 m
Depth ofthepool,h = 3.0m
Density of water, p 1000 kg/m3
Pressure due to column of Fluid, P = ρhg
Acceleration due to gravity, g = 9.8 m/s2
Substituting the values, P = ρhg
P = 100kgm-3 × (3.0m) × (9.8ms-2)
Pressure, P = 29400kgm-1s-2      ∵1Pa = 1kgm-1s-2
∴P = 29400 Nm-2 (or) 29400Pa

Samacheer Kalvi 9th Science Guide Chapter 3 Fluids

Question 6.
A body of volume 100 cc is immersed completely in the weight of water and the jar before immersion of the weight of water and jar after immersion.
Answer:
Volume of body completely immersed in water, V = = 100cc
Weight of water and jar before Immersion = 700g
The volume of jar immersed in water = Volume of water displaced = 100cc
Density of water = 1g/cm3
Mass of water displaced = Apparent weight loss
Mass of water displaced = Volume × density
= 100cc × 1g/cm3
Apparent weight loss of body = 100 g
Weight of jar and water after immersion = Weight of water and jar before immersion – Apparent weight loss
= 700g – 100g
= 600g.

IX. Assertion and Reason :

(a) Mark the correct choice as:
(a) If both Assertion and Reason are true and Reason is the correct explanation of Assertion.
(b) If both assertion and reason are true but reason is not the correct explanation of assertion.
(c) If assertion is true but reason is false.
(d) If assertion is false but reason is true.

Question 1.
Assertion (A) : The buoyant force on submerged rigid object can be considered to be acting at the centre of mass of object.
Reason (R) : In rigid body, force distributed uniformly through its volume can be considered to be acting at the centre of mass of the body.
Answer:
(c) Assertion is true but reason is false]
Reason : Centre of the mass of the body is fixed according to the distribution of density.

Question 2.
Assertion (A): The weight of the truck exerts less pressure on road.
Reason (R): The truck has six to eight wheels. As area increases pressure decreases.
Answer:
(a) Both Assertion and Reason are true and Reason is the correct explanation of Assertion

Question 3.
Assertion (A): Air gets thinner with increasing altitude.
Reason (R): The atmospheric pressure increases as we go up in mountains.
Answer:
(c) Assertion is true but the reason is false
Reason: The atmospheric pressure decreases as we go up in mountains.

Question 4.
Assertion (A) : Lactometer is used to check the purity of milk.
Reason (R) : Lactometer measures the cream content of milk.
Answer:
(b) Both assertion and reason are true but the reason is not the correct explanation of the assertion
(b) Directions: In each of the following questions, a statement of Assertion (A) is given followed by a corresponding statement of Reason (R) just below it. Of the statements, mark the correct answer as :

Samacheer Kalvi 9th Science Guide Chapter 3 Fluids

Question 5.
Assertion (A) : The force acting on the surface of a liquid at rest, under gravity, in a container is always horizontal.
Reason (R) : The forces acting on a fluid at rest have to be normal to the surface.
Answer:
(d) Assertion is false but reason is true
Reason: The force acting on the surface of liquid at rest, under gravity, in a container is always perpendicular due to the fact that molecules at the surface is attracted by the molecules below the surface (i.e) an inward attraction.

Question 6.
Assertion (A): A sleeping mattress is so designed that when you lie on it, a large area of your body comes in its contact.
Reason (R) : This reduces the pressure on the body and sleeping becomes comfortable.
Answer:
(a) Both Assertion and Reason are true and Reason is the correct explanation of Assertion]

Question 7.
Assertion (A): Wide wooden sleepers are kept below railway lines to reduce pressure on the railway tracks and prevent them from sinking in the ground.
Reason (R): Pressure is directly proportional to the area in which it is acting.
Answer:
(c) Assertion is true but the reason is false
Reason: Pressure is inversely proportional to the area in which it is acting.

Samacheer Kalvi 9th Science Guide Chapter 3 Fluids

X. Define the following

1. Define thrust: The force which produces compression is called thrust. Its S.I units is newton
2. Define pressure: Thrust acting normally to a unit area of a surface is called pressure. Its S.I. Unit is the pascal.
3. Define atmospheric pressure: The pressure exerted by the atmospheric gases on its surroundings and on the surface of the earth is called atmospheric pressure. 1 atm is the pressure exerted by a vertical column of mercury of 76 cm height.
4. Buoyant force: The upward force experienced by a body when partly or fully immersed in a fluid is called upthrust or buoyant force.
5. Pascal’s law: Pascal’s law states that an increase in pressure at any point inside a liquid at rest is transmitted equally and without any change, in all directions to every other point in the liquid.
6. Archimedes principle: Archimedes’ principle states that when a body is partially or wholly immersed in a fluid, it experiences an up thrust or apparent loss of weight, which is equal to the weight of the fluid displaced by the immersed part of the body.
7. Density: Density is known as mass per unit volume of a body. Its S.I. unit is kg nr5.
8. Relative density: Relative density is the ratio between the density of a substance and the density of water. The relative density of a body is a pure number and has no unit.
9. Hydrometer: A hydrometer is a device used to measure the relative density of liquids based on Archimedes’ principle.
10. Lactometer: Lactometer is a device used to check the purity of milk by measuring its density using Archimedes’principle.

Samacheer Kalvi 9th Social Science Guide Economics Chapter 3 Money and Credit

Tamilnadu State Board New Syllabus Samacheer Kalvi 9th Social Science Guide Pdf History Chapter 3 Money and Credit Text Book Back Questions and Answers, Important Questions Notes.

Tamilnadu Samacheer Kalvi 9th Social Science Solutions Economics Chapter 3 Money and Credit

Samacheer Kalvi 9th Social Science Money and Credit Text Book Back Questions and Answers

I. Choose the correct answer

  1. Certain metals like ______ (gold/iron) were used as a medium of exchange in ancient times.
  2. The Head Quarters of the RBI is at __________ (Chennai /Mumbai).
  3. International trade is carried on in terms of ________ (US Dollars / Pounds).
  4. The currency of Japan is ______ (Yen/Yuan)

Answer:

  1. Gold
  2. Mumbai
  3. US Dollars
  4. Yen

Samacheer Kalvi 9th Social Science Guide Economics Chapter 3 Money and Credit

II. Fill in the blanks

  1. ________ System can be considered as the first form of trade.
  2. money supply is divided into _______.
  3. The first printing press of the RBI was started at_________
  4. ________act as a regulator of the circulation of money
  5. the thesis about money by B.R. Ambedkar is _________

answer:

  1. barter
  2. four
  3. nasik
  4. reserve bank of india
  5. the probiem of the rupee – its origin and solutio

III. Match the following:

  1. US Dollar – (i) Automatic Teller Machine
  2. Currency in circulation – (ii) Substitute of money
  3. ATM – (iii) Universally accepted currency
  4. Salt – (iv) Saudi Arabia
  5. Riyal – (v) 85%

Answer:

  1. – (iii)
  2. – (v)
  3. – (i)
  4. – (ii)
  5. – (iv)

IV. Give Short Answer

Question 1.
Why was money invented?
Answer:

  1. If there were no money, we would be reduced to a barter economy.
  2. In the market, we don’t barter for individual goods.
  3. Instead, we exchange for goods (or) services for a common medium of exchange that is money.

Samacheer Kalvi 9th Social Science Guide Economics Chapter 3 Money and Credit

Question 2.
What is ancient money?
Answer:

  1. The metals can be termed as first form of currency.
  2. Gold, Silver and Copper wefe the metals used first.
  3. They were called ancient currency.

Question 3.
What were the items used as barter during olden days?
Answer:
Leather beads, shells, tobacco, salt, com, and even slaves were the items used as barter during the olden days.

Question 4.
What is spice route? Why was it called so?
Answer:

  1. Spice route was an ancient trade route followed by merchants, importers and exporters.
  2. The merchants followed spice routes of both land and sea from Malabar in India as far west as Morocco.
  3. Pepper, Spices, Pearls, Gems, Rubies and Muslin clothes were exported from the eastern sea of Tamil Nadu.
  4. Pepper and spices took a major share of the exports.
  5. Thus this route was called the spice route.

Question 5.
What is natural money?
Answer:
The metals such as silver and gold gained importance gradually all over the world. So, these metals were used as a standard value in the exchange of goods. This was called natural money.

Question 6.
Why were coins of low value printed in large quantities?
Answer:

  1. There were insufficient reserves of gold and silver.
  2. Mines also had a limited reserve of these metals.
  3. An alternative was found and coins were made using metals with lesser value.
  4. These were used to buy and sell goods of lesser value.
  5. It was used as the money of the poor people.

Samacheer Kalvi 9th Social Science Guide Economics Chapter 3 Money and Credit

Question 7.
What is meant by foreign exchange?
Answer:

  1. It is the conversion of one country’s currency into another. A country’s currency value may also be set by the country’s government.
  2. It is a system of trading in and converting the currency of one country into that of another.

V. Answer in detail

Question 1.
Explain how money is transacted in the digital world.
Answer:

  1. One has to visit the bank and fill in a challan or produce a cheque to withdraw money from his account.
  2. Now this practice is gradually vanishing.
  3. Instead, one can easily withdraw the necessary amount from an Automated Teller Machine (ATM), with the help of an ATM debit card.
  4. One can easily withdraw the money needed at any time at ATMs located everywhere.
  5. A person can deposit money in their account without visiting the branch.
  6. Similarly, credit cards are also available, through which things are bought on credit and the amount can be paid later.
  7. Now a days, instead of using cheques or Demand Drafts (DDs), online transactions through net banking are carried out.
  8. Through this, money is transacted to anyone who lives anywhere across the globe.
  9. Technology has advanced sci much that even mobile banking is widely used nowadays.

Question 2.
Explain in detail about the role of RBI in the country.
Answer:
A government has the responsibility to regulate money supply and oversee the monetary policy. Hoarding of money must be avoided at all costs in a country’s economy. Only then money can be saved in banks.

A major portion of the savings in banks are used for the development of industries, economic growth and various development schemes for the welfare of the poor.
All the major and important banks were nationalised (1969) in India. The Reserve Bank of India (RBI) regulates the circulation of currency in India.

The Reserve Bank of India started its operations on 1st April 1935. It was permanently moved to Mumbai from the year 1937. RBI was nationalised in 1949. 85% of the printed currency is let for circulation. According to the statistics available as on August 2018, currency worth of 19 lakh crore are in circulation.

Samacheer Kalvi 9th Social Science Guide Economics Chapter 3 Money and Credit

Question 3.
Write in detail about the various functions of money.
Answer:

  1. When money replaced the barter system, a lot of practical issues were solved.
  2. Money acts a medium of exchange, a unit of measurement, a store in value and a standard of deferred payments.
  3. plays an important role in transactions.
  4. Medium of Exchange – Money should be accepted liberally in exchange of goods and services in a country.
  5. Unit of Account – Money should be the common, standard unit of calculating a country’s total consumer goods, products, services etc. For example, if a book costs 50, it means that the price of the book is equal to 50 units of money. Money is used to measure and record financial transactions in a country.
  6. A Store of Value – Money is used as a store of purchasing power. It can be used to finance future payments.

VI. Write the correct statement

Question (a)

  1. The barter system flourished wherever civilizations thrived.
  2. This was the initial form of trade.

(i) 1 is correct; 2 is wrong
(ii) Both 1 and 2 are correct
(iii) Both 1 and 2 are wrong
(iv) 1 is wrong; 2 is correct
Answer:
(ii) Both 1 and 2 are correct

Question (b)

  1. Most of the international trade transactions are carried out in US dollars.
  2. No other country except the US carries out trade in the world.

(i) Both the statements are correct.
(ii) Both the statements are wrong.
(iii) 1 is correct; 2 is wrong
(iv) 1 is wrong; 2 is correct
Answer:
(iii) 1 is correct; 2 is wrong

VII. Project and Activity

Question 1.
Visit a local museum and collect information about the coins displayed there.
Answer:
Activity to be done by the students themselves

Samacheer Kalvi 9th Social Science Guide Economics Chapter 3 Money and Credit

Question 2.
Imagine you are going abroad for a Post Graduation course in architecture. Write a letter to the Branch Manager regarding an education loan.
Answer:
Date: 12th June 20xx.
From
xxxx yyyy
Chennai – 600 xxx.
To
The Branch Manager,
State Bank of India, xxx Branch,
Chennai – 600 xxx
Sir,
Sub: Request to sanction Educational Loan

I submit the following for your kind perusal.

I have completed my B.Arch. degree in Anna University. I have applied for a Post graduation course in architecture, that is, M. Arch at Kingston University in Australia. I have got the admission card also. But the cost of studies is too high. I request you to kindly sanction an educational loan for Rs.8 lakhs.

I am an account holder of your bank here. My SB Account No. is xxxx xxxx xxxxx.

I will be much obliged if you kindly consider my application and sanction the Educational Loan. Expecting your favourable reply.

Thanking you.
Yours faithfully,
[Signature]

VIII. Life Skills

Question 1.
Observe at a 20 rupee note. What is written on it?
Answer:
The following lines are written on it in Hindi and English.
Reserve Bank of India.
Guaranteed by the Central Government.
I promise to pay the bearer the sum of twenty rupees.
(Singend)
Governor

Samacheer Kalvi 9th Social Science Guide Economics Chapter 3 Money and Credit

Question 2.
Prepare a family budget for a month.
Answer:
Activity to be done by the students themselves based on the monthly income.

Intext HOTS

Question 1.
How important is foreign exchange to one’s country?
Answer:
The foreign exchange market is merely a part of the money market in the financial centres. The buyers and sellers of claim on foreign money and the intermediaries together constitute a foreign exchange market. It is not restricted to any given country or geographical area.

There is a wide variety of dealers in the foreign exchange market. Banks dealing in foreign exchange have branches with substantial balances in different countries. Through their branches and correspondents, the services of such banks, usually called “Exchange Banks,” are available all over the world.

Samacheer Kalvi 9th Social Science Money and Credit Additional Important Questions and Answers

I. Choose the correct answer

  1. Barter system involved the exchange of ______ (Goods/Money)
  2. NFC was introduced in Britain in the year ______ (2016/2008)
  3. The Chinese made coins out of ______ (Bronze/Copper)
  4. In 1999 mobile banks were used in ______ (USA/Europe)
  5. In educational loans the ______
  6. One rupee and two rupee notes were first printed in India in the year ______ (1917/1927)
  7. Security Priting and Minting Corporation of India Ltd. was started in ________(Mumbai/Dewas)

Answer:

  1. Goods
  2. 2008
  3. Bronze
  4. Europe
  5. Student
  6. 1917
  7. Dewas

Samacheer Kalvi 9th Social Science Guide Economics Chapter 3 Money and Credit

II. Fill in the blanks

  1. Exchange of goods means _____
  2. Countries bordering the Indian ocean used ______
  3. Paper money spread to Europe through the travels of __________
  4. A gold plated coin called the was introduced in Europe __________
  5. The Credit card was invented by __________
  6. In 2016 NFC got introduced in __________
  7. All the major and important banks were nationalised in India in __________
  8. There is no security required for the loan amount upto _________
  9. The relationship between money and price is connected with the policy __________
  10. Trades and small entrepreneurs need for their needs __________
  11. When the metal supply got limited 2 currency was introduced __________
  12. The medium of exchange in a country is __________

Answer:

  1. Barter System
  2. Shells
  3. Marco Polo
  4. Florin
  5. John Biggins
  6. India
  7. 1969
  8. 4 lakhs
  9. Monetary
  10. Credit
  11. Paper
  12. currency

III. Match the following

Question 1.

  1. European union – (i) Pound
  2. England – (ii) Ringgit
  3. China – (iii) Dollar
  4. Malaysia – (iv) Euro
  5. Australia – (v) Yuan

Answer:

  1. – (iv)
  2. – (i)
  3. – (v)
  4. – (ii)
  5. – (iii)

IV. Give short answers

Question 1.
What is ATM?
Answer:

  1. ATM means Automated Teller Machine, with the help of an ATM debit card.
  2. One can easily withdraw the money needed at any time at ATMs located everywhere.

Question 2.
How is the major portion of the savings in banks used?
Answer:
A major portion of the savings in banks are used for the development of industries, economic growth and various development schemes for the welfare of the poor.

Samacheer Kalvi 9th Social Science Guide Economics Chapter 3 Money and Credit

Question 3.
What phenomenon increased the importance of the market and money?
Answer:

  1. Growing crops and production are done on a commercial basis, rather than on a subsistence level.
  2. This phenomenon also increased the importance of the market and money.

Question 4.
What type of currency notes was available till 1947?
Answer:

  1. Till 1947, the currency notes with the image of King George VI were in circulation.
  2. After Independence, the Government of India issued currency notes.

Question 5.
Why do we say that money, a store of value?
Answer:

  1. Money is used as a store of purchasing power.
  2. It can be used to finance future payments.

Question 6.
What is meany by SHG?
Answer:
People who live in a particular place or those who are involved in a certain work join together as a group and start saving. These are called Self Help Groups (SHG).

V. Answer in detail

Question 1.
What are educational loans?
Answer:

  1. Educational loan attempts to meet the educational aspirations of the society.
  2. A student is the main borrower.
  3. A parent, spouse, or sibling can be the co-applicant.
  4. It is offered to students who want to pursue higher education in India or overseas.
  5. It can be taken for a full-time, part-time or vocational course, and Graduation or Post Graduation.
  6. There is no security required for the loan amount up to 4 lakhs
  7. The loan is repaid by the student generally after the employment.
  8. Students can apply through “Vidya Lakshmi Portal Education Loan Scheme”

Samacheer Kalvi 9th Social Science Guide Economics Chapter 3 Money and Credit

Question 2.
Explain the relationship between Money and Price.
Answer:

  1. The relationship between money and price is connected with the Monetary policy.
  2. There is a close relationship between the growth of money supply and inflation.
  3. Price controls play a very important role in a country’s economic stability.
  4. This role is played by RBI.
  5. Currency is the medium of exchange in a country.
  6. The Indian currency is called the Indian Rupee (INR).
  7. In a country the foreign currency is called foreign exchange.
  8. Purchasing capacity of all currencies in the world are compared using the US dollar as the standard currency.
  9. This value differs from country to country.
  10. Most of the international trade transactions are carried out in US dollar.

Question 3.
How is currency printed in India?
Answer:

  1. In 1925, the British government established a government press at Nasik in Maharashtra
  2. Currencies were printed three years later.
  3. In 1974, a press was started in Dewas, Madhya Pradesh.
  4. In the 1990’s two more presses were started in Mysuru, Karnataka, and Salboni in West Bengal to print bank notes.
  5. The Reserve Bank of India has the authority to decide the value of currency to be printed and how the amount should reach its destination safely.
  6. Though the RBI has the power to print up to ten thousand rupee notes, at present a maximum of upto rupees two thousand is printed.

Question 4.
Write a note on credit.
Answer:

  1. Farmers avail credit during monsoons for buying seeds, agricultural input and other expenses.
  2. Traders and small entrepreneurs need credit for their needs.
  3. Even large industries receive a credit to take up their new projects.
  4. Credit is available from:
    • Formal financial institutions like nationalised and private banks and co-operative banks
    • Informal financial institutions
    • Micro credit is received through Self Help Groups (SHG).
  5. As far as nationalised banks and co-operative banks are concerned the interest to credit is comparatively lesser and there is a guarantee for the pledged, goods.

Question 5.
What is an informal financial institution?
Answer:

  1. Informal financial institutions are easily approachable to customers with flexible procedures.
  2. But there are issues like the safety of items pledged high rates of interest and modes of recovery.
  3. The nationalised banks provide help to these groups through micro-credit.
  4. Credit is given through SHG for street vendors, fishermen, especially women, and the poor.
  5. In Tamil Nadu, all the banks have 10,612 branches, across the state.

Samacheer Kalvi 9th Social Science Guide Economics Chapter 3 Money and Credit

Question 6.
Why is foreign exchange important?
Answer:

  1. Without the ability to trade in different currencies, companies’ prospects would be limited.
  2. As a result, global economic growth would suffer.
  3. Investors also use the forex market.
  4. Those who seek international diversification benefits need to trade currencies to buy and sell foreign assets and securities.
  5. Foreign exchange reserve increases the confidence in the monetary and exchange rate policies of the government.
  6. Foreign exchange reserves come to the rescue of any country to absorb the distress related to such a crisis.
  7. In doing so the foreign exchange market is the mechanism that transfers purchasing power from one country to another.

VI. Write the correct statement

Question 1.
1. Mobile banking is not used.
2. Pepper and Spices took a major share of exports.
(i) Both 1 and 2 are correct
(ii) Both 1 and 2 are wrong
(iii) 1 is correct, 2 is wrong
(iv) 1 is wrong, 2 is correct
Answer:
(iv) 1 is wrong, 2 is correct

Samacheer Kalvi 9th Social Science Guide Economics Chapter 3 Money and Credit

Question 2.
1. Reserve Bank of India was permanently moved to Mumbai from 1935
2. Gold, silver and copper were called ancient money.
(i) Both 1 and 2 are correct
(ii) 1 is correct, 2 is wrong
(iii) 1 is wrong, 2 is correct
(iv) Both 1 and 2 are wrong
Answer:
(iii) 1 is wrong, 2 is correct

Samacheer Kalvi 9th Social Science Guide Economics Chapter 4 Tamilnadu Agriculture

Tamilnadu State Board New Syllabus Samacheer Kalvi 9th Social Science Guide Pdf Economics Chapter 4 Tamilnadu Agriculture Text Book Back Questions and Answers, Important Questions Notes.

Tamilnadu Samacheer Kalvi 9th Social Science Solutions Economics Chapter 4 Tamilnadu Agriculture

Samacheer Kalvi 9th Social Science Tamilnadu Agriculture Text Book Back Questions and Answers

I. Choose the correct answer

Question 1.
Irrigated land surface out of cultivable land is __________
(a) 27%
(b) 57%
(c) 28%
(d) 49%
Answer:
(b) 57%

Samacheer Kalvi 9th Social Science Guide Economics Chapter 4 Tamilnadu Agriculture

Question 2.
Out of the following which is not a food crop _________
a) Bajra
b) Ragi
c) Maize
(d) Coconut
Answer:
(d) Coconut

Question 3.
The productivity of paddy during the year 2014-2015
(a) 3,039 kg
(b) 4,429 kg
(c) 2,775 kg
(d) 3,519 kg
Answer:
(b) 4,429 kg

Question 4.
Both agricultural productivity and food productivity has ________
(a) decreased
(b) not stable
(c) remained stable
(d) increased
Answer:
(d) increased

Samacheer Kalvi 9th Social Science Guide Economics Chapter 4 Tamilnadu Agriculture

Question 5.
The North-East monsoon period in Tamil Nadu
(a) August – October
(b) September – November
(c) October – December
(d) November – January
Answer:
(c) October-December

II. Fill in the blanks

  1. The major occupation of people in Tamil Nadu is _________
  2. Tamil Nadu receives rainfall all from the _________monsoon.
  3. The total geographical area of Tamil Nadu is _________hectares.

Answer:

  1. Agriculture
  2. North-East
  3. one crore 30 lakh and 33 thousand

III. Match the following

  1. Non food crops – (i) 79,38,000
  2. Dhal – (ii) less than hectare of cultivable land
  3. North east monsoon – (iii) October – December
  4. Small farmers – (iv) Urad Dal, Toor Dal, Green grams
  5. No. of farmers in 2015 – 2016 – (v) Coconut, Channa

Answer:

  1.  – (v)
  2. – (iv)
  3. – (iii)
  4. – (ii)
  5. – (i)

IV. Give short answers

Question 1.
Give two examples for each food crop and non-food crops.
Answer:
Example for food crops: Paddy, Maize Example for non-food crops: Coconut, Cotton.

Samacheer Kalvi 9th Social Science Guide Economics Chapter 4 Tamilnadu Agriculture

Question 2.
What are the factors responsible for the changes in the cropping area?
Answer:
The size of the land, quality of the land, amount of rainfall received, reliable water source all contribute to a change in the cropping area.

Question 3.
Who monitors the quantity and quality of groundwater?
Answer:
The Union Ground Water Board is constantly monitoring the level and nature of groundwater. This continuous monitoring has categorized the Panchayat Union (blocks) in terms of the amount of groundwater used. 139 blocks in Tamilnadu are identified as excessive users of groundwater and 100 blocks as nearing the stage of excessive usage of groundwater. 11 blocks have been identified with reduced water quality. Only 136 blocks have enough quantity and quality water for usage.

Question 4.
On what factors does crop cultivation depend. List out the factors on which the crop cultivation depend.
Answer:
The crop cultivation depends on the amount of land being cultivated, the productivity of crops, source of water weather, rainfall etc.

Question 5.
Differentiate between small and marginal farmers.
Answer:

  1. Marginal farmers cultivate is an area of less than one hectare.
  2. Small farmers cultivate 1 – 2 hectares of land.
  3. In Tamil Nadu, the number of marginal farmers is decreasing.

V. Answer in detail

Question 1.
Give a note on the water resources of Tamil Nadu.
Answer:
Northeast monsoon (Oct-Dec) is a major source of water for Tamil Nadu. The Northeast monsoon rains are stored in reservoirs, lakes, ponds, and wells for cultivation. Conventional water bodies like lakes, ponds and canals provide water for agriculture in Tamil Nadu. 2,239 canals run through Tamil Nadu covering a length of 9,750 km. There are 7,985 small lakes, 33,142 large lakes, 15 lakh open wells and there are 3,54,000 borewells in the state where agriculture is carried out with the help of these water resources.

The area of land that is irrigated using water from lakes is very low. Nearly 3.68 lakh hectares of land obtain water from lakes. The canals provide water to 6.68 lakh hectares. Borewells irrigate 4.93 lakh hectares and open wells provide water to 1L91 lakh hectares of land.

Samacheer Kalvi 9th Social Science Guide Economics Chapter 4 Tamilnadu Agriculture

Question 2.
What are the problems faced by using groundwater for agriculture?
Answer:

  1. Tamil Nadu agriculture is dependent on groundwater.
  2. The use of groundwater for agriculture creates many hardships too.
  3. There would be no suffering if the amount of water taken from the underground and the amount of water that goes into the underground during the rainy season are equal.
  4. On the contrary, as the amount of water taken increases, the groundwater will go down resulting in complete dryness or change to unusable water.
  5. The Union Water Board is constantly monitoring the level and nature of groundwater.
  6. This continuous monitoring has categorized the Panchayat Union (Blocks) in terms of the amount of groundwater used.
  7. 139 Blocks are identified as excessive users of groundwater and 100 Blocks identified as nearing the stage of excessive usage of groundwater.
  8. blocks have been identified with reduced water quality. Only 136 blocks have enough quantity and quality of water for usage.
  9. From this, we clearly understand that Tamil Nadu agriculture is dependent on groundwater. It is very urgent and necessary to regulate the usage of underground water. This is very important for fertile farming.

Question 3.
Discuss the source of irrigation for agriculture.
Answer:
There are no perennial rivers in Tamil Nadu. Tamil Nadu receives the required water from the Northeast and Southwest monsoons. When the southwest monsoon rains are high in the catchment areas of the Cauvery River in Karnataka dams get filled and in turn, the Cauvery river in Tamil Nadu gets water.

Northeast monsoon (Oct-Dec) is a major source of water for Tamil Nadu. The Northeast monsoon rains are’ stored in reservoirs, lakes, ponds, and wells for cultivation. Conventional water bodies like lakes, ponds, and canals provide water for agriculture in Tamil Nadu. 2,239 canals run through Tamil Nadu covering a length of 9,750 km. There are 7,985 small lakes, 33,142 large lakes, 15 lakh open wells and there are 3,54,000 borewells in the state where agriculture is carried out with the help of these water resources.

The area of land that is irrigated using water from lakes is very low. Nearly 3.68 lakh hectares of land obtain water from lakes. The canals provide water to 6.68 lakh hectares. Borewells irrigate 4.93 lakh hectares and open wells provide water to 11.91 lakh hectares of land.

Samacheer Kalvi 9th Social Science Tamilnadu Agriculture Additional Important Questions and Answers

I. Choose the correct answer

Question 1.
Cholam cultivation takes place in TamilNadu is __________
(a) 7% land area
(b) 1% land area
(c) 12% land area
(d) 9% land area
Answer:
(a) 7% land area

Samacheer Kalvi 9th Social Science Guide Economics Chapter 4 Tamilnadu Agriculture

Question 2.
Krishi Karman award in related to __________
(a) cotton textile
(b) industrial growth
(c) food grain production
(d) educational growth
Answer:
(c) food grain production

Question 3.
Manila (groundnut) is grown in percent if the cultivated land.
(a) 6
(b) 3
(c) 10
(d) 12
Answer:
(a) 6

Question 4.
The third largest river in India __________
(a) Cauvery
(b) Godavari
(c) Krishna
(d) Mahanadhi
Answer:
(a) Cauvery

Samacheer Kalvi 9th Social Science Guide Economics Chapter 4 Tamilnadu Agriculture

Question 5.
In 2011, nearly of the women were involved in agriculture __________
(a) 35%
(b) 55%
(c) 25%
(d) 45%
Answer:
(b) 55%

II. Fill the blanks

  1. Most of the cultivations in Tamil Nadu are __________farmers
  2. A major portion of the employee involved in agricultural activities are __________labourers.
  3. In India the total land area under agriculture is __________fast.
  4. If there is good water for a land, it can be cultivated more than __________in a year.
  5. Nammaalvar believed in __________the’future generation of India.

Answer:

  1. marginal
  2. Landless
  3. shrinking
  4. one crop
  5. youth

III. Match the following

  1. Mettur Dam – (i) Tony Allen
  2. Maize – (ii) Kallanai
  3. Virtual water – (iii) Vanagam farm
  4. Cauvery – (iv) Highest – storage
  5. Nammaalvar – (v) Second

Answer:

  1. – (iv)
  2. – (v)
  3. – (i)
  4. – (ii)
  5. – (iii)

Samacheer Kalvi 9th Social Science Guide Economics Chapter 4 Tamilnadu Agriculture

IV. Give short answers

Question 1.
Write a note river Cauvery.
Answer:

  1. River Cauvery is the third largest river in India. Its length is 765 km.
  2. Cauvery passes Thiruchirapalli, Tanjavur, Srirangapattinam, Kumbakonnam.
  3. The dams constructed across Cauvery in Tamil Nadu are Mettur Dam, Kallanai

Question 2.
What Is National Ayush Movement?
Answer:

  1. The National Ayush Movement scheme is implemented by the central government.
  2. Its main aim is to save and extend the life of many medicinal herbs that grow only in the forest.
  3. This scheme is carried out with 60:40 shares from the central and state governments.

Question 3.
Write a note on Krlshi Karman award to TamllNadu.
Answer:

  1. Tamil Nadu has the highest GDP in India according to 2017
  2. Tamil Nadu tops in food grain production in 2015 – 2016 Prime Minister presented the Krishi Karman award to Tamil Nadu.
  3. Mettur dam has the highest storage of water in Tamilnadu for agricultural Purpose.

Samacheer Kalvi 9th Social Science Guide Economics Chapter 4 Tamilnadu Agriculture

Question 4.
Write a note on Farmer Producer Organizations (FPOs) in TamilNadu.
Answer:

  1. Small and marginal farmers in Tamil Nadu will be benefited from FPOs.
  2. Each of the producers’ groups have been given an investment grant of ?5 lakh to purchase farm equipment.
  3. Apart from using the equipment within the group, these can also be rented out to other farmers.
  4. The government also has a contract farming policy.

V. Answer in detail

Question 1.
Write about Nammaalvari journey towards Organic farming?
Answer:

  1. When Green Revolution was spreading throughout the nation, Nammalvar started his life journey towards organic farming.
  2. He resigned his regional Agricultural Developmental Officer post for this purpose.
  3. He believed in the youth the future generation of India.
  4. Nearly 6000 youth had completed training in organic farming in his Vanagam Farm.
  5. He spent most of his days in struggles for organic farming and travels campaigning for the same.
  6. He used only public transport.
  7. He felt that this was his small role in reducing environmental pollution.

Question 2.
Explain the term Virtual water.
Answer:

  1. The term virtual water was introduced by Tony Allen in 1990.
  2. The water consumed in the production process of an agriculture or industrial product has been called the virtual water.
  3. It is a hidden flow of water when food or other commodities are traded from one place to another..
  4. For instance it takes 1340 cubic meters of water to produce one metric ton of wheat.
  5. That is, if one metric ton of wheat is exported to another country, then, it means that 1340 cubic metre of water used to cultivate this amount of wheat is also being exported.
  6. India is the largest global freshwater user.
  7. India has been the fifth largest exporter of virtual water in the world.

Samacheer Kalvi 9th Social Science Guide Economics Chapter 4 Tamilnadu Agriculture

Question 3.
Write a note on Micro Irrigation.
Answer:

  1. Micro irrigation technology is a very good remedial to tackle shortage in irrigational water.
  2. This irrigation technology helps to have a higher yield when compared to the traditional irrigational methods.
  3. As only required amount of water is supplied at regular intervals, it increases the ability of water usage and productivity of the crop resulting in reduction of labour expenses and weed growth in the field.
  4. The government has taken many measures to implement micro irrigation for proper distribution of water to crops that require more water.

Question 4.
What are Farmer Producer Organisations (FPOs)?
Answer:

  1. In April 2013, the Government of India issued a National Policy and Process Guidelines on formation of FPOs.
  2. The year 2014 was observed as the “Year of Farmer Producer Organisations” by the Government of India.
  3. Its main idea of promoting and strengthening member based institutions of farmers.
  4. It aimed at engaging the farmer companies to procure agricultural products and sell them.
  5. Supply of inputs such as seed, fertilizer and machinery, market linkages, training & networking and financial and technical advice are also among the major activities of FPO

Samacheer Kalvi 9th Social Science Guide Economics Chapter 5 Migration

Tamilnadu State Board New Syllabus Samacheer Kalvi 9th Social Science Guide Pdf History Chapter 5 Migration Text Book Back Questions and Answers, Important Questions Notes.

Tamilnadu Samacheer Kalvi 9th Social Science Solutions Economics Chapter 5 Migration

Samacheer Kalvi 9th Social Science Migration Text Book Back Questions and Answers

I. Choose the correct Answer

Question 1.
According to the 2011 census, the total population of India was
(a) 121 crore
(b) 221 crore
(c) 102 crore
(d) 100 crore
Answer:
(a) 121 crore

Samacheer Kalvi 9th Social Science Guide Economics Chapter 5 Migration

Question 2.
_______ has recorded the maximum number of emigrants.
(a) Ramanathapuram
(b) Coimbatore
(c) Chennai
(d) vellore
Answer:
(c) Chennai

Question3.
during 2015,______of illiterates were migrants from Tamil Nadu.
(a) 7%
(b) 175%
(c) 23%
(d) 9%
Answer :
(a) 7%

Question4.
The poorer sections of the population migrate__________
(a) as a survival strategy
(b) to improve their living standards
(c) as a service
(d) to get experience
Answer:
(a) survival strategy

II. Fill in the blanks

  1. Migration is enumerated on_______and_____bases.
  2. The mobility of population in rural areas is ______than urban areas.
  3. In rural india ,as per census 2011,________percent of the population are counted as migrants.
  4. ______ is the major reason for female migration.
  5. Any migrant stream would consist of______ sub streams.

Answer:

  1. place of birth,place of residence
  2. greater
  3. 37
  4. marriage
  5. heterogeneous

III. Match the following

  1. Migration policy – (a) Work
  2. Female migrants – (b) low incidence of out migration
  3. Chennai – (c) maximum number of emigration
  4. Better off migrants – (d) marriage
  5. Salem – (e) to reduce the volume of migration
  6. Male migrants – (f) to improve the living standard

Answer:

  1. – (e)
  2. – (d)
  3. – (c)
  4. – (f)
  5. – (b)
  6. – (a)

IV.Give short answers

Question 1.
Enlist the reasons for migration.
Answer:
The reasons for migration include; Work/Employment, Business, Education, Marriage, and other such reasons.

Samacheer Kalvi 9th Social Science Guide Economics Chapter 5 Migration

Question 2.
What are the major factors responsible for female migrants in India?
Answer:

  1. Among female migrants, 70 % in India and 51 % in Tamil Nadu report marriage as their reason for migration, in 2011.
  2. Marriage and the movement associated with marriage appear to be a major factor responsible for women’s mobility in India and in Tamil Nadu

Question 3.
Name four districts in Tamil Nadu which record a low number of migration.
Answer:
Cuddalore, Karur, Thiruvannamalai, Vellore, Namakkal, Salem, Dindigul, Krishnagiri, Nilgiris and Dharmapuri districts record low number of emigrants.

Question 4.
What are the factors responsible for the poorer sections and better-off sections to migrate?
Answer:

  1. Poorer sections of the population people migrate as a survival strategy.
  2. Migrants from better-off sections move to their living standards.

Samacheer Kalvi 9th Social Science Guide Economics Chapter 5 Migration

Question 5.
List the four destinations and the percentage of migrants from Tamil Nadu.
Answer:
Of the total migrants who go to foreign countries, nearly 20% have chosen to go to Singapore, while 18% to the United Arab Emirates, 16% to Saudi Arabia, 13 % to the United States of America.

Question6.
What does the study reveal about the occupation undertaken by migrants?
Answer:

  1. The study clearly reveals a whole range of occupations undertaken by migrants.
  2. Highly skilled occupation on the one hand and low skilled occupations on the other with a large number of semi-skilled occupations in between.

V. Answer in detail

Question.1
State the aims of migration policies.
Answer:
Policies to address the problem of migration in developing countries like India essentially aim at the following:
To reduce the volume of migration: As a large part of the migration is a reflection of poverty
and insecurity faced by large sections of the rural people, the focus of intervention has to be in rural areas. Rural development policies to reduce poverty and insecurity would be essential to reduce the rate of migration.

To redirect the migrant streams: Redirection of migrant streams, away from big metropolitan cities is a desirable policy option. This policy can help in reducing spatial inequalities by suitable strategies, such as developing a more dispersed pattern of urbanisation.

Question.2
Discuss the patterns of migration.
Answer:

  1. The pattern of migration is very complex, comprising of number of streams.
  2. Rural to rural; rural to urban; urban to rural; urban to urban.
  3. Short, medium and long distance migration streams.
  4. Long-term stable migration and short-term circulatory type of movements.
  5. Each of these streams would consist of different types of migrants (from different social classes), each with its own reason for migration.
  6. The extent and nature of these rhigrant streams would essentially depend on.
    • Pressures and aspirations experienced hy people at the origin of migration.
    • Constraints imposed on mobility at the origin of migration.
    • Opportunities at the destination and
    • The cost of migration.

Question 3.
Elucidate about some of the interesting findings of migration in Tamil Nadu.
Answer:
In Tamil Nadu, two out of every five persons is reported to be a migrant in the year 2011. Incidence of migrants is higher in rural areas and larger among women. Tamil Nadu has a history of migration and people have moved for various reasons such as trade, business, employment etc, to various countries. During the colonial period, labourers had moved to other colonies seeking work and wages.

In the more recent period workers from Tamil Nadu have been moving to countries in the Gulf, the United States of America and Australia. In 2015, an independent research study was conducted to understand the level, nature and pattern of migration in Tamil Nadu. This study has made some interesting findings, as discussed below:

  • Of the total migrants in Tamil Nadu, 65 percent have migrated or moved abroad while 35 percent have moved within the country.
  • Chennai district has recorded the maximum number of emigrants followed by Coimbatore, Ramanathapuram and Tiruchirapalli districts.
    Cuddalore, Karur, Thiruvannamalai, Vellore, Namakkal, Salem, Dindigul, Krishnagiri, Nilgirfs and Dharmapuri districts record low number of emigrants. This study also provides information about the sex and destination of migrants Tamil Nadu.
  • Of the total migrants who go to foreign countries, nearly 20% have chosen to go to Singapore, while 18% to the United Arab Emirates, 16% to Saudi Arabia, 13 % to the United States of America; and Malaysia, Kuwait, Oman, Qatar, Australia and England are also refered as important destinations for migrants from Tamil Nadu in the year 2015.
  • Of the international migrants, 15 percent are women, while 85 percent are men.

Samacheer Kalvi 9th Social Science Guide Economics Chapter 5 Migration

Question 4.
Analyse the educational qualification of migrants from Tamil Nadu in 2015.
Answer:
On the question of educational qualifications of migrants from Tamil Nadu, the study reveals that in 2015 about 7 % were illiterates; 30 % have completed schooling ie. class 10; 10 % have completed class 12; 15 % had undergone some vocational training; 11 % were graduates; 12% were professionally qualified and 11 % had post graduate degrees.

VI. Write the correct statement.

Question 1.
In recent times workers from Tamil Nadu are moving to Africa.
Answer:
In the more recent period workers from Tamil Nadu have been moving to countries in the Gulf, United States of America and Australia.

Samacheer Kalvi 9th Social Science Guide Economics Chapter 5 Migration

Question 2.
In Tamil Nadu, the extent of migration is much higher in urban areas compared to rural areas.
Answer:
In Tamil Nadu, the extent of migration is much higher in rural are as compared to urban areas.

Question 3.
Any migrant stream would consist of homogenous sub-streams.
Answer:
Any migrant stream would consist of heterogenous-sub streams.

Question 4.
Two out of even, 10 persons are reported to be a migrant.
Answer:
Two out of every five persons are reported to be a migrant.

Samacheer Kalvi 9th Social Science Migration Additional Important Questions and Answers

I. Choose the correct Answer

Question 1.
In Tamil Nadu, migrants account for percent in rural areas.
(a) 38
(b) 41
(c) 28
(d) 50
Answer:
(b) 41

Samacheer Kalvi 9th Social Science Guide Economics Chapter 5 Migration

Question 2.
The driving force among men to migration is _________
(a) work
(b) employment
(c) tourism
(d) both a and b
Answer:
(d) both a and b

Question 3.
_________ Of the international migrants percent are women.
(a) 85
(b) 25
(c) 15
(d) 20
Answer:
(c) 15

Question 4.
Pick out the odd man _________
(a) Australia
(b) the USA
(c) Gulf countries
(d) Uganda
Answer:
(d) Uganda

II. Fill in the blanks.

  1. During the colonial period, labourers had moved to other colonies seeking ______
  2. Coimbatore has recored ______the number of emigrants next to Chennai.
  3. _____is the difference in social status, wealth or opportunity between people or groups.
  4. The process of moving from one place to another is known as ______
  5. Change in populating occurs due to births, deaths and ______

Answer:

  1. work and wages
  2. maximum
  3. Inequality
  4. migration
  5. migration

III. Match the following

  1. Place of birth – (i) Paul Harris Daniel
  2. Red Tea – (ii) Heterogeneous
  3. Migration – (iii) Destination
  4. Migrant stream – (iv) Lifetime migrant
  5. Kuwait – (v) trade

Answer:

  1.  – (iv)
  2. – (i)
  3. – (v)
  4. – (ii)
  5. – (iii)

IV.Give short answers

Question 1.
Mention the percentage of migrants in India as well as in Tamil Nadu.
Answer:

  1. The percentage of migrants was 37 percent in the country.
  2. It was at a much higher rate in Tamil Nadu at 43 percent.

Samacheer Kalvi 9th Social Science Guide Economics Chapter 5 Migration

Question 2.
How to determine the extent and nature of migration?
Answer:

  1. The extent and nature of migration in any society is basically determined by the nature of the development process experienced by that society.
  2. That is, the type and scale of development achieved by the agricultural and industrial sectors in an economy would determine the migratory patterns.

Question.3
What do the extent and nature of the migrant streams depend?
Answer:
The extent and nature of these migrant streams would essentially depend on:

  1. Pressures and aspirations experienced by people at the origin of migration.
  2. Constraints imposed on mobility at the origin of migration.
  3. Opportunities at the destination and availability of information regarding these opportunities.
  4. The cost of migration.

V.Answer in detail

Question 1.
Explain the concept of migration.
Answer:

  1. In any settlement-village or town change in population occurs due to birth, death and migration.
  2. Of these three components of population change, birth and death is clearly identifiable events while migration poses the maximum amount of problem with regards to its definition and measurement.
  3. As almost everyone keeps moving most of the time, it is not easy to define which of these moves have to be classified as migratory moves.
  4. In the Census of India, migration is enumerated on two bases – Place of birth and Place of residence.

Samacheer Kalvi 9th Social Science Guide Economics Chapter 5 Migration

Question 2.
Write a short note on “Red Tea”.
Answer:

  1. “Red Tea” is a very well known novel written by Paul Harris Daniel.
  2. The novel portraits the slavery life of plantation workers in Valparai.
  3. This novel depicts the blood-stained history of the workers that is hidden behind the green cover of the hills.
  4. This novel has been translated in Tamil by R. Murugavel in the name “Eriyum Panikkaadu” (6TifliL|LD usfilaafi
  5. The story starts with Karupan migrating to the hills with his wife in search of survival.
  6. The narrator of this story is Dr. Daniel, who comes there to treat the plantation employees.

VI. Write the correct statement

Question 1.
One usually associates mobility with female rather than male.
Answer:
One usually associate mobility with male rather than female.

Question 2.
Of the total migrants in Tamil Nadu, 65 percent have migrated toward rural areas.
Answer:
Of the total migrants in Tamil Nadu, 65 percent have migrated or moved abroad.

Samacheer Kalvi 9th Social Science Guide Economics Chapter 5 Migration

Question 3.
Work is the major factor responsible for female migrants in India.
Answer:
Work is the major factor responsible for male migrants in India.

Question 4.
Of the international migrants, 15 percent are men while 85 percent are women.
Answer:
Of the international migrants, 15 percent are women while 85 percent are men.

Samacheer Kalvi 9th Social Science Guide Civics Chapter 1 Forms of Government and Democracy

Tamilnadu State Board New Syllabus Samacheer Kalvi 9th Social Science Guide Pdf Civics Chapter 1 Forms of Government and Democracy Text Book Back Questions and Answers, Important Questions, Notes.

Tamilnadu Samacheer Kalvi 9th Social Science Solutions Civics Chapter 1 Forms of Government and Democracy

Samacheer Kalvi 9th Social Science Forms of Government and Democracy Text Book Back Questions and Answers

I. Choose the correct answer

Question 1.
A system of government in which one person reigns supreme, usually a king or queen, is called __________
(a) autocracy
(b) monarchy
(c) democracy
(d) republic
Answer:
(b) monarchy

Samacheer Kalvi 9th Social Science Guide Civics Chapter 1 Forms of Government and Democracy

Question 2.
A system of government with absolute power __________
(a) Aristocracy
(b) Theocracy
(c) Democracy
(d) Autocracy
Answer:
(d) Autocracy

Question 3.
Former Soviet Union is an example for __________
(a) aristocracy
(b) theocracy
(c) oligarchy
(d) republic
Answer:
(c) oligarchy

Question 4.
Select the odd one __________
(a) India
(b) USA
(c) France
(d) Vatican
Answer:
(d) Vatican

Samacheer Kalvi 9th Social Science Guide Civics Chapter 1 Forms of Government and Democracy

Question 6.
Kudavolai system was followed by __________
(a) Cheras
(b) Pandyas
(c) cholas
(d) Kalabhras
Answer:
(c) cholas

Question 7.
Direct Democracy in olden times existed
(a) In the republics of ancient India
(b) Among the USA (d) Among the UK
(c) In the city-state of ancient Greece
(d) Among the UK
Answer:
(c) In the city-state of ancient Greece

Question 8.
From which language was the term “Democracy” derived?
(a) Greek
(b) Latin
(c) Persian
(d) Arabic
Answer:
(a) Greek

Samacheer Kalvi 9th Social Science Guide Civics Chapter 1 Forms of Government and Democracy

Question 9.
In democracy the final authority’ rests with __________
(a) The Parliament
(b) The People
(c) The council of Ministers
(d) The President
Answer:
(b) The People

Question 10.
Which one of the country has the Presidential form of government
(a) India
(b) Britain
(c) Canada
(d) the USA
Answer:
(d) the USA

Question 11.
The largest democratic country in the world is __________
(a) Canada
(b) India
(c) USA
(d) China
Answer:
(b) India

Samacheer Kalvi 9th Social Science Guide Civics Chapter 1 Forms of Government and Democracy

Question 12.
Assertion (A): Direct democracy is practised in Switzerland.
Reason (R): People directly participates in decision making.
(a) Both (A) and (R) are true and (R) explains (A)
(b) Both (A) and (R) are true and (R) does not explain (A)
(c) (A) is correct and (R) is false
(d) (A) is false and (R) is true
Answer:
(a) Both (A) and (R) are true and (R) explains (A)

Question 13.
Assertion (A): India has a parliamentary form of democracy.
Reason (R): Indian Parliament comprises two houses.
(a) Both (A) and (R) are true and (R) explains (A)
(b) Both (A) and (R) are true and (R) does not explain (A)
(c) (A) is correct and (R) is false
(d) (A) is false and (R) is true
Answer:
(a) Both (A) and (R) are true and (R) explains (A)

Question 14.
The meaning of Franchise is __________
(a) Right to elect
(b) Right to vote for the poor
(c) Right to vote
(d) Right to vote for the rich
Answer:
(c) Right to vote

Question 15.
The grant of universal franchise creates __________
(a) Social equality
(b) Economic equality
(c) Political equality
(d) Legal equality
Answer:
(c) Political equality

Question 16.
Prime Minister of India is appointed by __________
(a) Lok Sabha
(b) Rajya Sabha
(c) Speaker
(d) President
Answer:
(d) President

Question 17.
The President of India can nominate __________
(a) 12 members to Lok Sabha
(b) 2 members of Rajya Sabha
(c) 12 members to Rajya Sabha
(d) 14 members of Rajya Sabha
Answer:
(c) 12 members to Rajya Sabha

Question 18.
The First general elections after independence in India were held in __________
(a) 1948-49
(b) 1951 – 52
(c) 1957- 58
(d) 1947-48
Answer:
(b) 1951 – 52

II. Fill in the blanks

  1. The Constitution of India was finally adopted on __________
  2. The two types of democracy are __________ and __________
  3. example for direct democracy is __________
  4. India has a __________ form of democracy.
  5.  __________ was the first Prime Minister of independent India.
  6. The first general elections were held in British India in the year __________
  7. The Parliament House in India was designed by _____ and _____

Answer:

  1. 26th November
  2. Direct and Indirect
  3. Switzerland
  4. Indirect/representative
  5. Jawaharlal Nehru
  6. 1920
  7. Edwin Lutyens and Herbert

III. Match the following

  1. Autocracy – (i) 18
  2. Right to vote – (ii) Arthashastra
  3. Chanakya – (iii) Vatican
  4. Theocracy -(iv) North Korea

Answer:

  1. – (iv)
  2. – (i)
  3. – (ii)
  4. – (iii)

IV. Give Short Answers

Question 1.
Give Abraham Lincoln’s definition of democracy.
Answer:
Abraham Lincoln defines democracy as a government of the people, by the people and for the people.

Samacheer Kalvi 9th Social Science Guide Civics Chapter 1 Forms of Government and Democracy

Question 2.
Mention the forms of democracy.
Answer:
There are two types of democracy. They are

  1. Direct democracy
  2. Indirect (Representative) democracy

Samacheer Kalvi 9th Social Science Guide Civics Chapter 1 Forms of Government and Democracy

Question 3.
Distinguish between direct and indirect democracy.
Answer:
Direct Democracy: Direct participation of the people
Example: Ancient Greek city-states, Switzerland

Indirect/ Representative Democracy: Indirect participation of the people
Example: India, USA, UK

V. Answer in detail.

Question 1.
What are the challenges to Indian democracy? Explain.
Answer:
Democracy is the dominant form of government in the contemporary world. It has not faced a serious challenge or a rival so far. In the last hundred years, there has been an expansion of democracy all over the world. The various aspects of democracy and its challenges are:

  1. Illiteracy
  2. Poverty
  3. Gender discrimination
  4. Regionalism
  5. Casteism, communalism, and religious fundamentalism
  6. Corruption
  7. Criminalisation of politics.
  8. Political violence

Samacheer Kalvi 9th Social Science Guide Civics Chapter 1 Forms of Government and Democracy

Question 2.
Explain the conditions necessary for the success of democracy in India.
Answer:
There are certain conditions that are necessary for the success of democracy in India. They are:

  1. Empowerment of the poor and illiterates to enjoy the goodness of democracy.
  2. Willingness among the elected people not to misuse their powerful position and public wealth.
  3. Eradication of social evils and dangers from which democracy suffers
  4. An impartial and efficient press to form public opinion
  5. Presence of strong public opinion
  6. The feeling of tolerance and communal harmony among the people
  7. Awareness among the people of the fundamental rights that they are entitled to enjoy
  8. Conscious check and vigilance on the working of the elected representatives
  9. Powerful and responsible opposition

Question 3.
What is your opinion about democracy in India?
Answer:
India has a parliamentary form of democracy. The Indian Parliament comprises the elected representatives of the people and makes the laws for the Country. The participation of people in the decision making and the consent of citizens are the two important elements of the parliamentary form of government in India.

India is the largest democratic country in the world. Democracy in India works on five basic principles. These are sovereign, socialist, secular, democratic, republic.

Every person who is a citizen of India and who is not less than 18 years of age can exercise their right to vote in India, based on universal adult suffrage. There is no discrimination based on a person’s caste, creed, religion, region, gender, and education when it comes to providing the right to vote.

VI. Project and Activity

Question 1.
Discuss in the class what is universal adult franchise? Why is it important?
Answer:

  1. Students can form different groups with the help of charts. They can bring out the salient features of the adult franchise and how it is implemented in real practice.
  2. Based on universal adult franchise, every person, who is a citizen of India and who is not less than eighteen years of age, can exercise their right to vote in India.
  3. There is no discrimination based on a person’s caste, creed, Religion, Gender, and Education when it comes to providing the right to vote.

Samacheer Kalvi 9th Social Science Guide Civics Chapter 1 Forms of Government and Democracy

Question 2.
“Democracy is the power of the majority which respects minority.” Discuss.
Answer:

  1. Democracy requires minority rights equally as it does majority rule the minority’s rights must be protected.
  2. The Indian constitution ensures justice, social, economic, and political, to all citizens.
  3. India declares herself a secular state
  4. Article 29 gives the religious and linguistic minorities the right to establish and manage educational institutions of their own.
  5. No discrimination on grounds of race, religion, caste, language
  6. Article 30 is vital to the protection and preservation of rights of the minorities
  7. Article 16 guarantees that in matters of public employment, no discrimination shall be made on the grounds of race, religion, caste or language
  8. Article 25 of the Indian constitution guarantees freedom of religion to every individual.
  9. On the whole, minorities of all kinds have very secure rights in India

Question 3.
Conduct a mock election in your class.
Answer:
Activity to be done by the students themselves

Question 4.
A group discussion on the merits and demerits of democracy of India in the classroom.

Country Name Type of Government Characteristics of the country’s government

Answer:
(a) Merits

  1. Responsible and accountable government
  2. Equality and Fraternity
  3. Sense of responsibility among common people
  4. Local self-government
  5. Development and prosperity for all
  6. Popular sovereignty
  7. Sense of Co-Operation and fraternal feeling.

(b) Demerits:

  1. Indirect or representative nature of democracy
  2. Lack of educated and experienced voters
  3. Equal voting right to both wise, average and innocent person
  4. Freedom to all shades of opinion.
  5. Delay in decision-making process

VII. HOTS

Question 1.
Will you have the right to equality under a dictatorship? What would be the attitude regarding public opinion in such a country?
Answer:

No; well, a dictatorship is when a country is run by a minority of people and the citizens of that country don’t have a choice of who runs it. If one person has to make all the decisions for a country, they might use their power badly because they have too much responsibility.

Question 2.
How does democracy lead to a peaceful and harmonious life among the citizens? Explain
Answer:

  1. In a democracy, fundamental rights are safeguarded as basic human freedoms which every Indian citizen has the right to enjoy for proper and harmonious development of personality,
  2. Democracies usually develop a procedure to conduct their competition.
  3. This reduces the possibility of tensions becoming explosives or violent.
  4. The ability to handle social differences, divisions and conflicts with a better manner is a
    democratic regime.

VIII. Life Skills

Select a group of countries. Research each country and tell what type of government it has: Aristocracy, Monarchy, Autocracy, Oligarchy, Theocracy, Democracy, Republic. Then, provide characteristics of this country that helped you determine the type of government.
Answer:
Samacheer Kalvi 9th Social Science Guide Civics Chapter 1 Forms of Government and Democracy

Samacheer Kalvi 9th Social Science Forms of Government and Democracy Additional Important Questions and Answers

I. Choose the correct answer

Question 1.
A system of government in which power is held by the nobility is called
(a) Monarchy
(b) Oligarchy
(c) Aristocracy
(d) Theocracy
Answer:
(c) Aristocracy

Samacheer Kalvi 9th Social Science Guide Civics Chapter 1 Forms of Government and Democracy

Question 2.
We find a system of government in which priests rule in the name of God or himself as a God in
(a) North Korea
(b) Vatican
(c) India
(d) Saudi Arabia
Answer:
(b) Vatican

Question 3.
“True Democracy cannot be worked by twenty men sitting at the centre. It has to be worked from below by the people of every village” – This statement was stated by
(a) Prof. Seeley
(b) Lowell
(c) Mahatma
(d) Dicey
Answer:
(c) Mahatma

Question 4.
General Elections were held in British India in
(a) 1910
(b) 1920
(c) 1930
(d) 1940
Answer:
(b) 1920

Question 5.
Freedom to practice any religion or reject all is expressed by the term
(a) Secular
(b) Socialist
(c) Republic
(d) Sovereign
Answer:
(a) Secular

Samacheer Kalvi 9th Social Science Guide Civics Chapter 1 Forms of Government and Democracy

Question 6.
Assertion (A): Indian President is selected indirectly
Reason (R): India is a Republic.
(a) Both (A) and (R) are true and (R) explains (A)
(b) Both (A) and (R) are true and (R) does not explain
(c) (A) is correct and (R) is false
(d) (A) is false and (R) is true.
Answer:
(a) Both (A) and (R) are true and (R) explains (A)]

Question 7.
Assertion (A): Lok sabha is called council of states.
Reason (R): People elect representatives to Lok Sabha.
(a) Both (A) and (R) are true and (R) explains (A)
(b) Both (A) and (R) are true and (R) does not explain
(c) (A) is correct and (R) is false
(d) (A) is false and (R) is true.
Answer:
(d) (A) is false and (R) is true

II. Fill in the blanks

  1. According to _________ the Democracy is a government in which everyone has a share
  2. When people themselves directly express their will on public affairs, the type of government is called _________
  3. The largest democracy in the world is _________
  4. The general elections are conducted by the _________ of India

Answer:

  1. Prof. Seeley
  2. Direct democracy
  3. India
  4. Election Commission

III. Match the following

  1. Aristocracy – (i) Oman
  2. Oligarchy – (ii) USA
  3. Monarchy – (iii) China
  4. Democracy – (iv) Britain’s Royal family

Answer:

  1. – (iv)
  2. – (iii)
  3. – (i)
  4. – (ii)

Question 2.

  1. Demos – (i) Power
  2. ratia – (ii) Upper House
  3. (c) Panchayat – (iii) People
  4. (d) Rajya Sabha – (iv) Local government

Answer:

  1. (a) – (iii)
  2. (b) – (i)
  3. (c) – (iv)
  4. (d) – (ii)

IV. Give short answers

Question 1.
What is government?
Answer:

  1. Government is a group of people that governs a community or unit.
  2. Forms of Government are

(a) Aristocracy
(b) Monarchy
(c) Autocracy
(d) Oligarchy
(e) Theocracy
(f) Democracy
(g) Republic

Question 2.
What is meant by the Parliamentary form of Government?
Answer:

  1. India has a parliamentary form of government.
  2. The Indian parliament comprises the elected representatives of people who make laws for the country.
  3. The participation of people in the decision making and the consent of citizens are the two important elements of the parliamentary form of government in India.

Question 3.
What is democracy?
Answer:

  1. Democracy is a form of government that allows people to choose their rulers.
  2. Only leaders elected by the people should rule the country.
  3. People have the freedom to express views, freedom to organize and freedom to protest

Samacheer Kalvi 9th Social Science Guide Civics Chapter 1 Forms of Government and Democracy

Question 4.
Mention the features of Democracy.
Answer:

  1. Elected representatives of people and final decision-making power to the representatives.
  2. Free and fair elections.
  3. Universal adult franchise with each vote having equal value.
  4. Fundamental rights and protection of individual freedom.

Question 5.
State the importance of the Sixty-first Constitutional Amendment Act.
Answer:

  1. On 28th March 1989 – the voting age was reduced from 21 to 18 by the sixty-first Constitutional Amendment Act.
  2. It was passed during the time of Rajiv Gandhi, the late Prime Minister of India

Question 6.
When were the first General elections held in Independent India?
Answer:

  1. General elections to the first Lok Sabha since independence were held in India between 25th October 1951 and 21st February 1952
  2. The Indian National Congress (INC) emerged victorious into power by winning 364 of the 489 seats
  3. Jawaharlal Nehru became the first democratically elected Prime Minister of the country

V. Answer in detail

Question 1.
Write about elections in India
Answer:

  1. India has a Quasi-federal government, with elected representatives at the federal, state and local levels.
  2. The general elections are conducted by the Election Commission of India.
  3. At the National level, the head of the government, the President of India appoints the Prime Minister, who enjoys majority in the Lok Sabha.
  4. All members of the Lok Sabha, (except two Anglo Indians, who can be nominated by the President of India) are directly elected through the general election
  5. In India, the general elections take place every five years in normal circumstances.
  6. Members of the Rajya Sabha, the Upper House of the Indian Parliament, are elected by an Electoral college consisting of elected members of the legislative assemblies of the States and for the Union Territories of India.
  7. The first – general elections in free india to the first Lok Sabha took place between 25th Oct, 1951 and 21st February 1952

VI. Hots

Question 1.
Is multi party system beneficial for India? Discuss.
Answer:

  1. In general, a multi party political system ensures that there will never be a single majority.
  2. The multi party system satisfies the goal of democracy of people being able to influence the decisions.
  3. India is a huge country. It needs parties that actually have political ideologies.
  4. Multi party system can be good for countries where development parametric are already very high.
  5. Constructive criticism by a strong apposition is absolutely essential for parliamentary democracy.
  6. India is a vast – country with social and geographical diversities. So here the multiparty system allows a variety of interests and opinion to enjoy political representation.
  7. If people use their voting right in proper manner, definitely multiparty system will help to have multiple ideas to improve the nation.

Samacheer Kalvi 9th Social Science Guide Civics Chapter 1 Forms of Government and Democracy

Question 2.
Conduct a study on General elections in India
Answer:

  1. India has a Quasi – federal government with elected representatives at the federal, state and local levels.
  2. The General elections are conducted by the Election Commission of India
  3. At the National level, the head of the government, the President of India appoints the Prime Minister.
  4. All members of Lok Sabha (except two Anglo Indians, who can be nominated by the President of India) are directly elected through General elections.
  5. It takes place every 5 yrs, in normal circumstances
  6. Members of the Rajya Sabha, the Upper House of the Indian Parliament, are elected by an Electoral college consisting of elected members of the legislative assemblies of the States and for the Union Territories of India.

VII. Rearrange the jumbled words.

Question 1.

  1. EDUEFMR
  2. EINRSVOEG
  3. NTRYIAFTRE
  4. OPTCNOREIAO
  5. WSRAESNEA

Answer:

  1. FREEDOM
  2. SOVEREIGN
  3. FRATERNITY
  4. CO-OPERATION
  5. AWARENESS

Samacheer Kalvi 9th Social Science Guide Civics Chapter 1 Forms of Government and Democracy

Question 2.

  1. UIPCBL
  2. IOMSALCIS
  3. EITNCIZS
  4. OICDSEIN

Answer:

  1. PUBLIC
  2. SOCIALISM
  3. CITIZENS
  4. DECISION

Samacheer Kalvi 9th Social Science Guide Geography Chapter 5 Biosphere

Tamilnadu State Board New Syllabus Samacheer Kalvi 9th Social Science Guide Pdf Geography Chapter 5 Biosphere Text Book Back Questions and Answers, Important Questions, Notes.

Tamilnadu Samacheer Kalvi 9th Social Science Solutions Geography Chapter 5 Biosphere

Samacheer Kalvi 9th Social Science Biosphere Text Book Back Questions and Answers

I. Choose the correct answer

Question 1.
The coldest biome on Earth is __________
(a) Tundra
(b) Taiga
(c) Desert
(d) Oceans
Answer:
(a) Tundra

Samacheer Kalvi 9th Social Science Guide Geography Chapter 5 Biosphere

Question 2.
This is the smallest unit of biosphere __________
(a) Ecosystems
(b) Biome
(c) Environment
(d) None of the above
Answer:
(d) Ecosystems

Question 3.
Nutrients are recycled in the atmosphere with the help of certain micro organisms, referred to as __________
(a) Producers
(b) Decomposers
(c) Consumers
(d) None of the above
Answer:
(d) None of the above

Question 4.
To which climatic conditions are Xerophytic plants specifically adapted to?
(a) Saline and sandy
(b) Limited moisture availability
(c) Cold temperature
(d) Humid
Answer:
(a) Saline and sandy

Question 5.
Why is the usage of rainforest biomes for large scale agriculture unsustainable?
a) because it is too wet.
b) because the temperature is too warm,
c) because the soil is too thin.
d) because the soil is poor.
Answer:
d) because the soil is poor

Questions 6-8 are assertion type questions. Directions :
(a) Both assertion (A) and reason(R) are true; R explains A
(b) Both assertion(A) and reason(R) are true; R does not explain A
(c) A is true; R is false
(d) Both A and R are false

Question 6.
A: Heterotrophs do not produce their own food.
R : They depend on autotrophs for their nourishment.
Answer:
(a) Both assertion (A) and reason(R) are true; R explains A

Question 7.
A : Hotspots are the regions characterised by numerous endemic plants and animal species
living in a vulnerable environment.
R : To manage and focus on conservation work more effectively, researchers identified hotspots.
Answer:
(a) Both assertion (A) and reason(R) are true; R explains A

Samacheer Kalvi 9th Social Science Guide Geography Chapter 5 Biosphere

Question 8.
A: The number of gorillas in Africa has plummeted by 60% in the past twenty years.
R : Non intervention of human beings in the forest areas.
Answer:
(c) A is true; R is false

II. Fill in the Blanks

  1. An area where animals, plants and micro organisms live and interact with one another is known _____
  2. __________ are also called Heterotrophs.
  3. __________ is a system of interlocking and independent food chains,
  4. __________ is an extensive large ecosystem.
  5. The vegetative type commonly found in desert biomes is called __________
  6. __________ is an aquatic biome that is found where freshh water and salt water mix

Answer:

  1. Eco System
  2. consumers
  3. Food web
  4. A Biome
  5. Xerophytes
  6. Estuary

III. Answer the following in brief

Question 1.
What is Biosphere?
Answer:
The biosphere is a life-supporting layer that exists on the earth’s surface. This layer on earth encompasses the Lithosphere, Hydrosphere, and Atmosphere. It includes flora and fauna that thrive on or near the earth’s surface.

Samacheer Kalvi 9th Social Science Guide Geography Chapter 5 Biosphere

Question 2.
What is an ecosystem?
Answer:

  1. An ecosystem is a community, where all living organisms live and interact with one another and also with their non-living environment such as land, soil, air, water etc.
  2. Ecosystems range in size from the smallest units (Eg: bark of a tree) that can sustain life to the global ecosystem or ecosphere. (Eg: Cropland, Pond ecosystem, Forest ecosystem, Desert ecosystem etc.).
  3. Biosphere harbours all ecosystems on the earth and sustains life forms including mankind.

Question 3.
What does the term ‘biodiversity’’ mean?
Answer:
Biodiversity or biological diversity refers to a wide variety of living organisms (plants, animals and other microorganisms) which live in a habitat. It is highly influenced by topography, climate as well as human activities.

Question 4.
What is meant by loss of bio diversity?
Answer:

  1. The extinction of species (flora and fauna) due to human and natural influences is called loss of biodiversity.
  2. The biodiversity loss has a great impact on mankind and also affects land, water, air etc.
  3. Habitat destruction due to deforestation, population explosion, pollution and global warming are the major cause for loss of biodiversity.
  4. Sometimes, habitat loss is so severe or happens so quickly that it results in a species being eliminated from the planet.

Samacheer Kalvi 9th Social Science Guide Geography Chapter 5 Biosphere

Question 5.
Mention the various terrestrial biomes.
Answer:
The major terrestrial biomes of the world are:

  1. Tropical Forest Biomes
  2. Tropical Savanna Biomes
  3. Desert Biomes
  4. Temperate Grassland Biomes
  5. Tundra Biomes

IV. Give reasons for the following

Question 1.
Producers are also called autotrophs.
Answer:
Producers are self-nourishing components of the ecosystem. Hence they are called Autotrophs. They are found both on land and water, e.g. Plants, Algae, Bacteria, etc.

Question 2.
Biosphere provides a stable ecosystem.
Answer:

  1. Ecosystems range in size from the smallest units that can sustain life to the global ecosystem or ecosphere.
  2. The biosphere harbours all ecosystems on the earth and sustains life forms including mankind. Therefore Biosphere provides a stable ecosystem.

V. Distinguish between the following.

Question 1.
Producers and Decomposers.
Answer:
Producers:

  1. Producers are self-nourishing components of the ecosystem.
  2. Hence they are called Autotrophs.
  3. They are found both on land and in water. Eg. Plants, Algae, Bacteria etc.

Decomposers:

  1. Decomposers are some organisms that are incapable of preparing its own food.
  2. They live on dead and decaying plants and animals.
  3. Hence they are called Saprotrophs. Eg. Fungus, mushrooms etc.

Samacheer Kalvi 9th Social Science Guide Geography Chapter 5 Biosphere

Question 2.
Terrestrial biomes and Aquatic biomes.
Answer:
Terrestrial biomes:

  1. Terrestrial biomes is a group of living organisms that live and interact with one another on land. They are
  2. mainly determined by temperature and rainfall.
  3. Some of the major terrestrial biomes of the world are:
    • Tropical Forest Biomes
    • Tropical Savanna Biomes
    • Desert Biomes
    • Temperate Grassland Biomes
    • Tundra Biomes

Aquatic biomes:

  1. Aquatic biome is a group of living organisms that live and interact with one. another and its aquatic environment for nutrients and shelter.
  2. Like terrestrial biomes, aquatic biomes are influenced by a series of abiotic factors.
  3. It is broadly classified as:
    1. fresh water biomes and
    2. marine biomes.

Question 3.
Tropical vegetation and Desert vegetation.
Answer:
Tropical vegetation:

  1. Tropical forests have the highest biodiversity and primary productivity of any of the terrestrial biomes.
  2. These regions have very dense forests.
  3. The chief trees found here are rubber, bamboo, ebony, etc.

Desert vegetation:

  1. Due to the lack of rainfall and arid conditions, these regions do not possess any vegetation but have a special vegetation type called Xerophytes.
  2. As the soil is sandy and saline, deserts remain agriculturally unproductive.
  3. Drought resistant thorny scrubs and bushes, palms are found here.

Samacheer Kalvi 9th Social Science Guide Geography Chapter 5 Biosphere

Question 4.
Savannas and Tundra.
Answer:
Savannas:

  1. Tropical Savannas are generally found between tropical forests and deserts.
  2. Tropical Savanna biomes are found between 10° to 20° North and South latitudes.
  3. This biome is generally hot and dry and experiences moderate to low rainfall.
  4. The grass which grow here are tall and sharp.

Tundra:

  1. 1. Tundra low lands are found where the ground remains frozen.
  2. 2. Greenland, Arctic and Antarctic region and Northern parts of Asia, Canada, Europe fall in this Biome.
  3. 3. These regions are also called Barren lands.
  4. This biome experiences long severe winter and short cool summer.

VI. Answer the following in a paragraph

Question 1.
Explain the various components of the ecosystem.
Answer:
An ecosystem is a community, where all living organisms live and interact with one another and also with their non-living environment such as land, soil, air, water etc. Ecosystems range in size from the smallest units (e.g. bark of a tree) that can sustain life to the global ecosystem or ecosphere. (e.g. Cropland, Pond ecosystem, Forest ecosystem, Desert ecosystem etc.). Biosphere harbours all ecosystems on the earth and sustains life forms including mankind.
Components of the ecosystem:
An ecosystem consists of three basic components, namely
(A) Abiotic components
(B) Biotic components and
(C) Energy component

A) Abiotic Components: Abiotic components include the non-living, inorganic, physical and chemical factors in the environment, e.g. Land, Air, Water, Calcium, Iron etc.

B) Biotic Components: Biotic components include plants, animals and microorganisms. Biotic components can be classified into three categories:

  • Producers are self-nourishing components of the ecosystem. Hence they are called Autotrophs. They are found both on land and water, e.g. Plants, Algae, Bacteria etc.
  • Consumers are those that depend on producers, directly or indirectly. Hence they are called Heterotrophs.

C) Energy Components: All organisms in the biosphere use energy to work and convert one form of energy into another. The Sun is the ultimate source of energy for the biosphere as a whole. The solar energy gets transformed into other forms of energy through the various components in the ecosystem. The producers, consumers and decomposers contribute a lot to the energy flow in an ecosystem.

Samacheer Kalvi 9th Social Science Guide Geography Chapter 5 Biosphere

Question 2.
Write a paragraph on the functions of an ecosystem.
Answer:

  1. The living organisms form an interacting set of flora and fauna which are organized into trophic levels, food chains and food webs.
  2. The functioning of an ecosystem depends on the pattern of the energy flow, as it helps in the distribution and circulation of the organic and inorganic matter within an ecosystem.
  3. Energy flow generally takes place in a hierarchical order in an ecosystem through various levels.
  4. These levels are called trophic levels.
  5. The chain of transformation of energy from one group of organisms to another, through various trophic levels is called a food chain.
  6. A system of interlocking and interdependent food chains is called a food web.

Question 3.
Explain about the aquatic biomes on Earth.
Answer:
An aquatic biome is a group of living organisms that live and interact with one another and its aquatic environment for nutrients and shelter. Like terrestrial biomes, aquatic biomes are influenced by a series of abiotic factors. It is broadly classified as freshwater biomes and marine biomes.

A. Freshwater Biomes: It comprises lakes, ponds, rivers, streams, wetlands etc. It is influenced by various abiotic components such as the volume of water, water flow, the composition of oxygen, temperature, etc. Humans rely on freshwater biomes for drinking water, crop irrigation, sanitation and industry. Water lily, lotus, duckweeds etc. are the common plants found here. Trout, salmon, turtles, crocodiles etc. are the animals found here.

B. Marine Biomes: They are the largest aquatic biomes on earth. They are continuous bodies of saltwater and provide a wide range of habitats for marine plants and animals. Coral reefs are the second kind of marine biomes within the ocean. Estuaries, coastal areas where salt water and fresh water mix, form a third unique marine biome. As water provides maximum mobility to marine organisms, nutrients are circulated more quickly and efficiently here than the terrestrial biomes. Apart from animals, plants such as kelp, algae, phytoplankton etc. also grow in water. Aquatic biomes are not only important for plants and animals, but also for humans. Humans use aquatic biomes for water, food and leisure activities. Some of the threats and issues to aquatic biomes are overfishing, pollution and a rise in sea level.

Samacheer Kalvi 9th Social Science Guide Geography Chapter 5 Biosphere

VII. Find out the dates for the following

Question 1.

  1. World Wild Life Day – _______
  2. International Day of Forest – _______
  3. World Water Day – _______
  4. Earth Day – _______
  5. World Environment Day – _______
  6. World Oceans Day – _______

Answer:

  1. 3rd March
  2. 21st March
  3. 22nd March
  4. 22nd April
  5. June 5th
  6. 8th June

VIII. Map Study

Question 1.
Locate the following on the world outline map.

  1. Prairies
  2. Downs
  3. Tundra Biomes
  4. Equatorial Biomes

Samacheer Kalvi 9th Social Science Guide Geography Chapter 5 Biosphere

IX. Picture Study

Question 1.
Narrate the given web of Arctic Thundra in your own words

Samacheer Kalvi 9th Social Science Guide Geography Chapter 5 Biosphere

Answer:

  1. Sun → Lichen → Lemming → Wolf
  2. Sun → Lichen → Caribou → Wolf
  3. Sun → Grasses → Arctic Hare → Hawk
  4. Sun → Grasses → Arctic Hare → Polar Bear
  5. Sun → Grasses → Arctic Hare → Wolf
  6. Sun → Grasses → Lemming → Hawk
  7. Sun → Grasses → Lemming → Wolf
  8. Sun → Grasses → Musk Ox
  9. Sun → Artie Wildflower → Leming → Hawk
  10. Sun → Artie Wildflower → Leming → Wolf
  11. Sun → Artie Wildflower → Caribou → Polar Bear
  12. Sun → Artie Wildflower → Caribou → Wolf

Intext Activity

Question 1.
Narrate the forest ecosystem in your own words.
Answer:

  1. A forest ecosystem is a large area of land that’s covered in trees and other woody plants and filled with living animals. There are three main types of forests: tropical rain forests, deciduous forests, and coniferous forests.
  2. Tropical rain forests are found near the equator (the center of Earth), where they are warm all year round. It usually rains in rain forests every day, and there are many different species of animals that live in the different levels of the rain forest.
  3. Deciduous forests are made up of trees that shed their leaves in autumn. Worms, snails, and spiders enjoy their rich soil, and they have warm summers and cold winters. In the winter, animals that live in deciduous forests hibernate, or sleep through the winter, and birds migrate to warmer areas in the world. Raccoons, rabbits, and squirrels are common animals found in deciduous forests.
  4. Coniferous forests have vegetation composed primarily of cone-bearing needle-leaved or scale-leaved evergreen trees, found in areas that have long winters and moderate to high annual precipitation.

Samacheer Kalvi 9th Social Science Guide Geography Chapter 5 Biosphere

Question 2.
Find the etymology of Herbivores, carnivores, omnivores and scavengers using dictionary
Answer:
Etymology

  1. Herbivores Meaning – Plant Eating
  2. Herba Meaning – Plant / Vorare – Swallow
  3. Carnivores Meaning – Flesh Eating
  4. Cami Meaning – Flesh / Vorare – Swallow
  5. Omnivores Meaning – feeding on a variety of food of both plant and animal origin
  6. Omni Meaning – All / Vorare – Swallow
  7. Scavengers Meaning – an animal that feeds on carrion, dead plant material or refuse.
  8. Scavage Meaning – search or inspect through rubbish things

Samacheer Kalvi 9th Social Science Biosphere Additional Important Questions and Answers

I. Fill in the Blanks

  1. All living things large or small are grouped into _________
  2. The area in which an animal, plant or micro organisms lives is called its _________
  3. The chain of transformation of energy from one group of organisms to another through various trophic levels is called a _________
  4. The Extinction of spices is called _________
  5. In Temperate Grass Lands Biome higher precipitation leads to _________ grass.
  6. In Temperate Grassland Biomes lower precipitation leads to _________ grass.
  7. Tundra Biomes are also called _________
  8. Lakes, ponds, rivers, streams, wetlands together known as _________ biomes.
  9. In aquatic ecosystem, there is abundant water with limited _________ supply.
  10. Terrestrial animals use only 1 – 2% of energy to obtain _________
  11. The wide variety of living organisms that are found on the planet is called _________
  12. The study about freshwater ecosystem is called _________
  13. The study of the sources, development and history of a word is called _________
  14. There are _________ Biosphere Reserves in India.

Answer:

  1. Species
  2. habitat
  3. Food chain
  4. Loss of Biodiversity
  5. tall and soft
  6. short and soft
  7. Barren Lands
  8. Fresh water
  9. oxygen
  10. oxygen
  11. biodiversity
  12. Limnology
  13. Etymology
  14. 18

II. Choose the correct answer

Question 1.
The life-supporting layer is known as ________
(a) Atmosphere
(b) Hydrosphere
(c) Lithosphere
(d) Biosphere
Answer:
(d) Biosphere

Samacheer Kalvi 9th Social Science Guide Geography Chapter 5 Biosphere

Question 2.
The branch of science that deals with an ecosystem are called ________
(a) Etymology
(b) Geology
(c) Limnology
(d) Ecology
Answer:
(d) Ecology

Question 3.
Abiotic components include ________
(a) Non-living things
(b) Living things
(c) only plants
(d) only animals
Answer:
(a) Non-living things

Question 4.
Zebra and goat come under ______ consumers.
(a) Primary
(b) Secondary
(c) Tertiary
(d) None of the above
Answer:
(a) Primary

Question 5.
A healthy ecosystem provides _________
a) clean water
b) enriched soil
c) raw materials
d) All of the above
Answer:
(d) All of the above

Questions 6-8 are assertion type questions:
Directions
(a) Both assertion (A) and reason (R) are true; R explains A
(b) Both assertion(A) and reason (R) are true; R does not explain A
(c) A is true; R is false
(d) Both A and R are false

Samacheer Kalvi 9th Social Science Guide Geography Chapter 5 Biosphere

Question 6.
Assertion (A): A stable biosphere has to be conserved.
Reason (R): The loss of biodiversity affects land, water, air etc.
Answer:
(a) Both assertion (A) and reason (R) are true; R explains A

Question 7.
Assertion (A): In temperate grassland biomes pastoral industry becomes the main occupation.
Reason (R): Apart from wheat cultivation, tall and short soft grass are grown in the
temperate grassland biomes.
Answer:
(a) Both assertion (A) and reason (R) are true; R explains A

Question 8.
Assertion (A): Biosphere Reserves are established in India.
Reason (R): Today’s loss of biodiversity is habitat alteration caused by human activities.
Answer:
(a) Both assertion (A) and reason(R) are true; R explains A

III. Match the following

  1. World wild life day – (i) 8th June
  2. International day of forest – (ii) 22nd April
  3. World water day – (iii) 3rd March
  4. Earth day – (iv) 22nd March
  5. (e) World oceans day – (v) 21st March

Answer:

  1. – (iii)
  2. – (v)
  3. – (iv)
  4. – (ii)
  5. – (i)

IV. Give short answers

Question 1.
What is considered a hotspot?
Answer:
An ecological region that has lost more than 70% of its original habitat is considered a hot spot.

Samacheer Kalvi 9th Social Science Guide Geography Chapter 5 Biosphere

Question 2.
In India where do we find hot spots?
Answer:
Hotspots in India are the Himalayas, Western Ghats, Indo Burma Region and Sundaland.

Question 3.
Mention the human settlement in the Tropical Forest Biomes.
Answer:

  1. The Tropical Forest Biomes have very dense forests.
  2. So human settlements are found scattered here,
  3. They sustain their livelihood through food gathering, fishing, lumbering and shifting cultivation.

Question 4.
What threat is posed by the savanna grasslands?
Answer:

  1. Of late, parts of the savanna grasslands are being converted into farmlands.
  2. This poses a great threat to a wide range of fauna.
  3. For Eg. The population of the big cats like cheetah, lion etc. are dwindling drastically.

Question 5.
What has been identified by the U.S. National Cancer Institute?
Answer:

  1. The U.S. National Cancer Institute has identified about 70% of the plants used for treating cancer.
  2. There are found only in rain forests.

Question 6.
Name the common animals found in the Tropical Savanna Biomes.
Answer:

  1. In the Tropical Savanna biomes the lion, leopard, tiger, deer, zebra, giraffe etc. are the common animals found.
  2. Flora such as Rhodes grass, red oats grass, lemon grass etc. are found in this biome.

Question 7.
Write about Oasis.
Answer:

  1. An oasis is a fertile fresh water source found in deserts and semi-arid regions.
  2. Oases are fed by springs.
  3. Crops like date palms, figs, citrus fruits, maize etc. are cultivated near these oases.

Samacheer Kalvi 9th Social Science Guide Geography Chapter 5 Biosphere

Question 8.
Mention the different names of the Temperate grass lands.
Answer:

  1. Temperate grass lands are called differently in different parts of the world.
  2. They are Prairies – North America, Steppes – Eurasia Pampas – Argentina and Uruguay Downs – Australia and Newzealand

Question 9.
What is a Biosphere Reserve?
Answer:
A Biosphere Reserve is a special ecosystem or specialised environment with flora and fauna that require protection and nurturing. There are 18 Bioshpere Reserves in India.

Question 10.
Explain the following terms
(a) Herbivorous
(b) Carnivorus
(c) Ommivorous
(d) Scavengers
Answer:
(a) Herbivorous: A herbivores is an animal that gets its energy from eating plants and only plants. Many herbivores have special digestive systems that let them digest all kinds of plants including grasses. Eg.-, deer, rabbits, cows, sheep, goats, elephants, giraffes, horses and pandas.

(b) Carnivores: A Carnivore is an animal that gets food from killing and eating other animals. Or they scavenge their dead flesh. Eg., Hyenas, Wolves, Mountains lions, Polar Bears.

(c) Omnivores: An omnivore is a kind of animal that eats either other animals or plants Eg. Raccoons, pigs, rats, chickens, crows etc.

(d) Scavengers: Scavengers feed partly or wholly on the bodies of dead animals. Eg., Jackals, Leopards, Lions, Vulture etc.

V. Distinguish the following

Question 1.
Tropical Grasslands and Temperate grassland.
Answer:
Tropical grasslands:

  1. Tropical grasslands are generally found between tropical forests and desserts.
  2. This biome is generally hot and dry and experiences moderate to low rainfall.
  3. The grass which grow here are tall and sharp.

Temperate grasslands:

  1. Temperate grasslands are usually found in the interior of the continents and are characterized by large seasonal temperature variations, with warm summer and cold winter.
  2. The type of grassland in these regions strongly depends upon precipitation.
  3. Higher precipitation leads to tall and soft grass and lower precipitation leads to short and soft grass.

Samacheer Kalvi 9th Social Science Guide Geography Chapter 5 Biosphere

VI. Give reasons for the following

Question 1.
In tropical savannas the chief occupation is herding.
Answer:
The tropical savannas biomes are generally hot and dry and experience moderate to low rainfall. Tall and sharp grass is grown. Hence the chief occupation of the people here is herding.

Question 2.
Tropical Forest Biomes have economic importance.
Answer:

  1. The Amazon basin, Congo basin and Indonesian islands, under this biomie, have very dense forests and so have great economic importance.
  2. The chief trees found here are rubber, bamboo, ebony etc.

Question 3.
Why do people in Tundra region shift their settlement frequently?
Answer:
The harsh environment makes people change their settlement frequently. People are nomadic, depending on hunting and fishing. The population here is very sparse.

VII. Answer in detail

Question 1.
Write a note on Biodiversity.
Answer:
(a) Biodiversity :

  1. Biodiversity or biological diversity refers to a wide variety of living organisms (plants, animals and other micro organisms) which live in a habitat.
  2. It is highly influenced by topography climate as well as human activities.
  3. It represents the strength of the biological resources of a place on earth.
  4. In biodiversity, each species, no matter how big or small, has an important role to play in the ecosystem.
  5. It maintains the ecological balance and facilitates social benefits such as tourism, education, research etc. over an area.

(b) Loss of biodiversity:

  1. The extinction of species (flora and fauna) due to human and natural influences is called loss of biodiversity.
  2. The biodiversity loss has a great impact on mankind and also affects land, water, air etc.
  3. Habitat destruction due to deforestation, population explosion, pollution and global warming are the major cause for loss of biodiversity.
  4. Sometimes, habitat loss is so severe or happens so quickly that it results in a species being eliminated from the planet.
  5. Scientists are still trying to decide what caused the mass extinction of dinosaurs.

Samacheer Kalvi 9th Social Science Guide Geography Chapter 5 Biosphere

Question 2.
Explain the need for conservation.
Answer:

  1. The biosphere extends from the deep ocean trenches to lush rain forests.
  2. People play an important role in maintaining the flow of energy in the biosphere.
  3. At the same time, the primary cause of today’s loss of biodiversity is habitat alteration caused by human activities.
  4. The ever increasing population results in over exploitation of biological resources.
  5. This has an adverse impact on flora and fauna on earth.
  6. There are places on earth that are both biologically rich and deeply threatened.
  7. Hence it is man’s duty to conserve and care for the earth and make it a better place to live in.

Samacheer Kalvi 9th Social Science Guide Civics Chapter 3 Human Rights

Tamilnadu State Board New Syllabus Samacheer Kalvi 9th Social Science Guide Pdf Civics Chapter 3 Human Rights Text Book Back Questions and Answers, Important Questions, Notes.

Tamilnadu Samacheer Kalvi 9th Social Science Solutions Civics Chapter 3 Human Rights

Samacheer Kalvi 9th Social Science Human Rights Text Book Back Questions and Answers

I. Choose the correct answer

Question 1.
Apartheid’was followed by ____________
(a) South Sudan
(b) South Africa
(c) Nigeria
(d) Egypt
Answer:
(b) South Africa

Question 2.
____________ right exercises in the formation and administration of a government.
(a) Social
(b) Economic
(c) Political
(d) Cultural
Answer:
(c) Political

Samacheer Kalvi 9th Social Science Guide Civics Chapter 3 Human Rights

Question 3.
A 10 year old boy is working in a shop. Which right can you use to recover him?
(a) Right to equality
(b) Right to freedom
(c) Right against child labour exploitation
(d) Right to freedom of Religion
Answer:
(c) Right against child labour exploitation

Question 4.
What is the time limit to get the information from RTI Act 2005?
(a) 20 days
(b) 25 days
(c) 30 days
(d) 35 days
Answer:
(c) 30 days

Question 5.
Which of the following statements are true?
(i) The state Human Rights commission was established in 1993.
(ii) It has the power of a civil court.
(iii) It’s power extend beyond the state.
(iv) It can also recommend compensation to victims.
(a) i and ii are true
(b) i and iii are true
(c) i, ii and iii are true
(d) ii, iii and iv are true
Answer:
(ii), (ii) and (iv) are true

Samacheer Kalvi 9th Social Science Guide Civics Chapter 3 Human Rights

Question 6.
Consider the following statements.
Assertions (A): Rights and duties are the two sides of the same coin.
Reason (R): We have a right to freedom of religions. We have to promote harmony and
the spirit of the people of other religions.
(a) Both A and R are correct and R explains A
(b) Both A and R are correct but R does not explain A
(c) A is correct but R is false
(d) A is false but R is correct
Answer:
(a) Both A and R are correct and R explains A

Question 7.
According to the UNO, a child is a person who has not completed the age of ________ years
(a) 12
(b) 14
(c) 16
(d) 18
Answer:
(d) 18

Samacheer Kalvi 9th Social Science Guide Civics Chapter 3 Human Rights

Question 8.
Kailasta Satyarthi and Malala have been awarded Nobel Prize for ____________
(a) Literature
(b) Peace
(c) Physics
(d) Economics
Answer:
(b) Peace

II. Fill in the blanks

  1. The Universal Declaration of Human Rights Contains ____________ articles.
  2. The fundamental Duties were incorporated in the Constitution by ____________ Amendment Act.
  3. The National Human Rights commission was established on ____________
  4. Indian state to implement women ancestral property Act in 1989 was ____________

Answer:

  1. 30
  2. 42nd
  3. 12th October 1993
  4. Tamil Nadu

III. Match the following

  1. Right to Vote – (i) Cultural Rights
  2. Right to form union – (ii) Right against exploitation
  3. Right to preserve tradition – (iii) Political Rights
  4. The Hindu Succession Act – (iv) Right to freedom
  5. Child labour – (v) 2005

Answer:

  1. – (iii)
  2. – (iv)
  3. – (i)
  4. – (v)
  5. – (ii)

IV. Give short answers

Question 1.
What is Human Right?
Answer:
The U.N.O defines Human rights as “The right inherent to all human beings, regardless of race, gender, nationality, ethnicity, language, religion or any other status. Everyone is entitled to these rights without discrimination”.

Samacheer Kalvi 9th Social Science Guide Civics Chapter 3 Human Rights

Question 2.
What are the fundamental rights?
Answer:
The fundamental rights are :

  1. Right to Equality
  2. Right to Freedom
  3. Right against Exploitation
  4. Right to Freedom of Conscience and Religion
  5. Cultural and Educational Rights for minorities
  6. Right to Constitutional Remedies

Question 3.
What are the Child Rights defined by the UNO?
Answer:

  • Right to life
  • Right to the family environment
  • Right to Education
  • Right to benefit from Social security
  • Right against sexual exploitation
  • Right against sale or trafficking
  • Right against other forms of exploitation like Child labour.

Question 4.
Write a short note on the Right to Constitutional Remedies,
Answer:

  1. Fundamental Rights are guaranteed by the Constitution.
  2. By this right, a person can adopt Constitutional means and approach a court if he is denied the Fundamental Rights.
  3. The court then issues orders which are called ‘Writs’ to the government to restore the rights to the citizen.
  4. The Constitutional Remedies put to right anything which may be wrong in terms of the Constitution.
  5. This right, therefore, protects and safeguards all other rights.

Question 5.
Define: POCSO
Answer:

  1. The state should protect children from sexual exploitation and abuse when they are forced or persuaded to take part in sexual activities physically or mentally.
  2. The Protection of Children from Sexual Offences Act, 2012.
  3. Regards the best interest of the child as being of paramount importance at every stage.

Samacheer Kalvi 9th Social Science Guide Civics Chapter 3 Human Rights

Question 6.
Why do children need special attention?
Answer:

  1. Children are the future citizens of a nation.
  2. They should grow with warmth and interest.
  3. It helps the child feel secure and valued.
  4. From birth children need experiences and relationships that show them they are valued, capable human beings, who bring pleasure to others.
  5. Due special attention, the child’s image builds up overtime in a positive manner.

Question 7.
What are the contributions to labourers by B.R, Ambedkar?
Answer:
Dr. B.R. Ambedkar’s contribution to labourers.

  • Reduction in Factory Working Hours (8 hours a day)
  • Compulsory Recognition of Trade Unions
  • Employment Exchange in India
  • Employees State Insurance (ESI)
  • Minimum Wages
  • Coal and Mica Mines Provident Fund

Question 8.
‘All are equal before law’. But we have enacted a separate law for women – Justify
Answer:

  1. We have enacted a separate law for women to review the constitutional and legal safeguards for woman.
  2. It recommends remedial measures.
  3. Advises the government on all matters of policy affecting the welfare and development of women in the country.
  4. Women’s rights under the Constitution of India mainly include equality, dignity and freedom from discrimination.

Samacheer Kalvi 9th Social Science Guide Civics Chapter 3 Human Rights

Question 9.
Write about the Right against exploitation.
Answer:
It is against the law to employ children below 14 years of age in mines, factories, or other occupations. Neither contractor nor an employer can force a worker to do a job against their will.

Question 10.
Differentiate Fundamental Rights and Human Rights.
Answers:
Fundamental Rights:

  1. The elemental rights of the citizens of a country, which are listed in the constitution and enforceable under the law is known as fundamental rights.
  2. Fundamental rights include only those rights which are basic to a normal life.
  3. Fundamental rights are guaranteed under the constitution of the country.

Human Rights:

  1. The rights that a human being deserves to survive with respect and freedoms.
  2. Human rights include those rights which are basic to real life and are absolute, i.e. it cannot be taken away.
  3. Human rights are recognised at the international level.

V. Answer in detail

Question 1.
A paragraph about UDHR.
Answer:

  1. The Universal Declaration of Human Rights is a milestone document in the history of human rights.
  2. The Declaration was proclaimed by the United Nations General Assembly in Paris on 10th December 1948.
  3. The first time it sets out the fundamental human rights to be universally protected and the UDHR has been translated into many languages.
  4. There are 30 articles in the Universal Declaration of Human Rights and it guarantees freedom of expression as well as civil, political, social, economic and cultural rights. These rights apply to all people, irrespective of their race, gender and nationality, as all people are born free and equal.

Samacheer Kalvi 9th Social Science Guide Civics Chapter 3 Human Rights

Question 2.
What are the fundamental duties? How would you follow these in your school premises?
Answer:
The Fundamental Duties were incorporated in the Constitution by the 42nd Amendment Act in 1976. The Constitution states eleven Fundamental Duties. They are,

  1. Respect for the Constitution and its ideals and institutions, the National Flag and the National Anthem.
  2. To follow and cherish the noble ideals which inspired our National Struggle for freedom.
  3. To uphold and protect the sovereignty, unity and integrity of India.
  4. To defend the country and render national service when called upon to do so.
  5. To promote harmony and spirit of common brotherhood amongst all the people of India, transcending religious, linguistic, regional or sectional diversities, to renounce practices derogatory to the dignity of women.
  6. To value and preserve the rich heritage of our composite culture.
  7. To protect and improve the natural environment including forests, lakes, rivers and wildlife and have compassion on living creatures.
  8. To develop the scientific temper, humanism and the spirit of inquiry and reform.
  9. To safeguard public property and to abjure from violence.
  10. To strive towards excellence in all spheres of individual and collective activity, so that the nation constantly rises to higher levels of endeavour and achievements.
  11. To provide opportunities for education by the parent and guardian to their child or ward upto the age of 14 years.
  12. I would follow the relevant fundamental duties with determination and discipline.

Question 3.
How does the National Human Rights Commission protect our rights?
Answer:

  • To inquire into the violation of human rights or negligence in the prevention of such violation by a public servant
  • To intervene in court proceedings relating to human rights
  • To undertake and promote research in the field of human rights
  • To engage in human rights education among various sections of society
  • To encourage the effects of NGOs and institutions working in the field of human rights.

Samacheer Kalvi 9th Social Science Guide Civics Chapter 3 Human Rights

Question 4.
What are the benefits for workers provided by labour law?
Answer:
(a) Due to Labour law, workers enjoy the following benefits,

  1. Reduction in Factory Working Hours (8 hours a day)
  2. Compulsory Recognition of Trade Unions
  3. Employment Exchange in India
  4. Employees State Insurance (ESI)
  5. Minimum Wages
  6. Coal and Mica Mines Provident Fund

(b) Women workers benefit the following,

  1. Mines Maternity Benefit Act
  2. Women Labour Welfare Fund
  3. Women and Child Labour Protection Act
  4. Maternity Benefit for Women Labour
  5. Restoration of Ban on Employment of Women on Underground Work in Coal Mines.

Question 5.
How do you enjoy the fundamental rights in your life?
Answer:
Right to Equality before the law and equal protection of the law. Prohibition of discrimination on the grounds of religion, caste, race, gender, or place of birth is offensive and one can seek justice from the court.
Right to Freedom: Six different types of freedom are mentioned in the Constitution. They are

  • Freedom of speech and expression.
  • Freedom to assemble peacefully without arms.
  • Freedom to form associations and unions.
  • Freedom to reside and settle in any part of India.
  • Freedom to move freely throughout the territory of India.
  • Freedom to practice any profession and carry on any occupation, trade, or business.

Right against Exploitation:
It is against the law to employ children below 14 years of age in mines, factories, or other occupations. Neither contractor nor an employer can force a worker to do a job against their will.

Samacheer Kalvi 9th Social Science Guide Civics Chapter 3 Human Rights

VI. Project and Activity

Question 1.
How do you protect yourself from child abuse / sexual exploitation and trafficking.
Answer:
Activity to be done by the students themselves

Question 2.
Write an article titled “My country, My Rights”.
Answer:
My Country, My Rights
Our country is a democratic country. We live independently with self-respect. We have lots of rights and responsibilities of our country. Rights and responsibilities are two sides of a coin and both go side by side. If we have rights we must have their corresponding responsibilities too. The rights and duties of each citizen are very valuable and inter-related.

Fundamental rights are given to each and every citizen for the basic and essential conditions of good life for the citizens’ welfare. Without such rights, no Indian citizen can develop his/her personality and confidence. These fundamental rights are preserved in the Indian Constitution.

There are six fundamental rights of the Indian citizens without which no one can live in the democratic manner. It means that democracy in the country can work only if its citizens have rights. Such rights prevent the government from being dictatorial and cruel. Fundamental rights help people in their moral, material and personality development. In case of rights violations of someone, courts can protect and safeguard the citizens.

Our country provides to all our citizens the necessary fundamental civil rights such as Right to Equality, Right to Freedom, Right against Exploitation, Right to Freedom of Conscience and Religion, Cultural and Educational Rights for minorities, Right to Constitutional Remedies. As being the citizen of the country, our responsibilities and duties are:

We must respect the National Flag and National Anthem.

We should respect and obey the laws of our country.

We should enjoy rights and freedom under the limit without interfering with freedom and rights of others.

We should be ready to protect our country whenever required.

We should respect and protect national property and public property (such as railways, post offices, bridges, roadways, schools, colleges, historical buildings, places, forests, etc).

We should pay our taxes with honesty in the stipulated time.

We should not waste electricity, water, natural resources, public property, etc.

So, we have to perform our duties sincerely to be a honest citizen, which is necessary for the development of our country.

Samacheer Kalvi 9th Social Science Human Rights Additional Important Questions and Answers

I. Choose the correct answer

Question 1.
UDHR played a crucial role in promoting ___________
(a) Individual Rights
(b) Fundamental Rights
(c) Human Rights
(d) None of the above
Answer:
(c) Human Rights

Samacheer Kalvi 9th Social Science Guide Civics Chapter 3 Human Rights

Question 2.
The life of people became meaningful through ___________
(a) Fundamental Rights
(b) Civics Rights
(c) Political Rights
(d) Cultural Rights
Answer:
(a) Fundamental Rights

Question 3.
Fundamental duties were incorporated in the Indian Constitution in the year ___________
(a) 1980
(b) 1975
(c) 1976
(d) 1950
Answer:
(c) 1976

Question 4.
Childline in India is ___________
(a) 100
(b) 108
(c) 1098
(d) 1028
Answer:
(c) 1098

Question 5.
NCW was constituted to safeguard ___________
(a) Children
(b) Labourers
(c) Students
(d) Women
Answer:
(d) Women

Samacheer Kalvi 9th Social Science Guide Civics Chapter 3 Human Rights

Question 6.
Which of the following statements are true?
(i) The general explanations of Human Rights by UDHR is not a legally binding document.
(ii) UDHR has political and moral importance.
(a) (i) is correct (ii) is wrong
(b) (i) is wrong (ii) is correct
(c) Both (i) and (ii) are wrong
(d) Both (i) and (ii) are correct
Answer:
(d) Both (i) and (ii) are correct

Question 7.
Consider the following statements-
Assertion (A): Child marriages should be avoided.
Reason (R) : When girls get married early, they lose many privileges thereby affecting the society as a whole.
(a) Both (A) and (R) are correct and (R) explains (A)
(b) Both (A) and (R) are correct but (R) does not explain (A)
(c) (A) is correct and (R) is false
(d) (A) is false and (R) is correct.
Answer:
(a) Both (A) and (R) are correct and (R) explains (A)

II. Fill in the blanks

  1. Gandhi was evicted from a first class compartment on the night of ___________
  2. UNO was established in the year ___________
  3. UNO was formed after ___________
  4. In 1994 ___________ became the President of South Africa.
  5. The milestone document in the history of human rights is ___________
  6. Political rights are given to the citizens by ___________
  7. The written order from the court or other legal authority is called a ___________
  8. Protection and promotion of human rights is India in the responsibility of ___________
  9. Malala shared the Nobel Peace prize with ___________
  10. One of the RTI activists is ___________

Answer:

  1. 7th June 1893
  2. 1945
  3. Second world war
  4. Nelson Mandela
  5. the Universal Declaration of Human rights
  6. Law
  7. Writ
  8. NHRC
  9. Kailash Satyatarathi
  10. Aruna Roy / Nikil Dey

III. Match the following

Question 1.

  1. F. W. de Klerk – (i) Fundamental duty
  2. To defend the country – (ii) Fundamental Right
  3. Freedom of Speech – (iii) SHRC
  4. Recommend compensation to victims – (iv) Child Right
  5. Family Environment – (v) President

Answer:

  1. – (v)
  2. – (i)
  3. – (ii)
  4. – (iii)
  5. – (iv)

IV. Give short answers

Question 1.
What are Extended rights?
Answer:
The Child rights, SC and ST rights, Women rights, Right to Information Act (RTI) and Labour laws come under Extended rights.

Samacheer Kalvi 9th Social Science Guide Civics Chapter 3 Human Rights

Question 2.
What is Apartheid?
Answer:
Apartheid means social discrimination. Apartheid was the highest form of discrimination that existed in South Africa. Places of residences were determined by racial classification. It was the governing policy in the country by the minority whites over the majority non-whites. The people of South Africa protested against racial discrimination.

Question 3.
What is Apartheid?
Answer:

  1. Apartheid means social discrimination.
  2. Apartheid was the highest form of discrimination that existed in South Africa.
  3. Places of residences were determined by racial classification.
  4. It was the governing policy in the country by the minority whites over the majority non-whites.
  5. The people of South Africa .protested against racial discrimination.

Samacheer Kalvi 9th Social Science Guide Civics Chapter 3 Human Rights

Question 4.
Write a note on Nelson Mandela.
Answer:

  1. Nelson Mandela raised his voice against Apartheid.
  2. When he organised defiant campaigns against the government, he was imprisoned.
  3. He was released in 1990 by President F.W. de Klerk.
  4. The efforts taken by Mandela and de Klerk put an end to apartheid.
  5. In 1994, a general election was held and Nelson Mandela, the leader of the African National Congress, became President.

Question 5.
What do the 30 articles of UDHR guarantee?
Answer:

  1. There are 30 articles in the Universal Declaration of Human Rights.
  2. It guarantees freedom of expression as well as Civil, Political, Social, Economic and Cultural Rights.
  3. These rights apply to all people, irrespective of their race, gender and nationality, as all people are bom free and equal.

Question 6.
What are the social and economic rights assured by UDHR?
Answer:

  1. Social rights are necessary for full participation in society.
  2. Economic rights guarantee every person to have conditions under which they are able to meet their needs.
  3. They are a part of a range of legal principles through which economic equality and freedom are preserved in a State.

Question 7.
What are the cultural rights assured by UDHR?
Answer:
Cultural rights are human rights that aim at assuring the enjoyment of culture and its components in conditions of equality, human dignity and non-discrimination.

Samacheer Kalvi 9th Social Science Guide Civics Chapter 3 Human Rights

Question 8.
What does the term Civil rights refer to?
Answer:

  1. The term ‘Civil rights’ refers to the basic rights afforded by laws of the government.
  2. It is guaranteed to every person regardless of race, nationality, colour, gender, age, religion etc.

Question 9.
What Is meant by political rights?
Answer:

  1. Political rights exercised in the formation and administration of a government.
  2. They are given to the citizens by law.
  3. These rights give power to the citizens to participate either directly or indirectly in the administration.

Question 10.
Write a note on the Right to Equality.
Answer:

  1. Right to Equality refers to equality before the law and equal protection of the law.
  2. Prohibition or discrimination on the grounds of religion, caste, races, gender or place of birth is offensive.
  3. One can seek justice from the court if such a situation does arise.

Question 11.
Explain the Right against exploitation.
Answer:

  1. It is against the law to employ children below 14 years of age in mines, factories, or other occupations.
  2. Neither contractor nor an employer can force a worker to do a job against their will.

Question 12.
How are people assure of freedom of religion?
Answer:

  1. The right to freedom of conscience and religion gives the citizens freedom to follow and practice a religion of their choice.
  2. All citizens have the freedom of conscience or ideas.
  3. The citizens also have the freedom to follow their own ways of practicing any religion.

Samacheer Kalvi 9th Social Science Guide Civics Chapter 3 Human Rights

Question 13.
What is a Writ?
Answer:
Writ is a written order from the court or other legal authority ordering to do an act or not to do it.

Question 14.
How are senior citizens legally protected?
Answer:

  1. Senior citizens Act was passed in 2007 by the Government of India to maintain the welfare of parents.
  2. This Act is a legal obligation for children and heirs to provide maintenance to senior citizens and parents.

Question 15.
What is NHRC?
Answer:

  1. The National Human Rights Commission (NHRC) is an autonomous body constituted on 12th October 1993 under the protection of the Human Rights Act, 1993.
  2. It consists of a chairman and a few other members.
  3. NHRC is responsible for the protection and promotion of human rights in India.
  4. The Act defines the right relating to life, liberty, equality, and dignity of the individual guaranteed by the Constitution or embodied in the international covenants.

Question 16.
What is SHRC?
Answer:

  1. SHRC refers to State Human Rights Commission.
  2. Every state in India has a State Human Rights Commission established in accordance with the power conferred on the state under section 21 of the Protection of Human Rights Act, 1993.
  3. The protection and promotion of human rights constitute the principal concern of the Commission.

Question 17.
When were the Rights of the child accepted by the UNO?
Answer:

  1. A child is a person who has not completed the age of 18 years i.e. a minor as per UNO.
  2. This principle is exhibited in Articles 25 of the Universal Declaration of Human Rights.
  3. Based on these principles, the declaration of the Rights of the child was accepted and adopted in the UN General Assembly on 20th November, 1989.

Question 18.
What is Childline?
Answer:

  1. Child line (1098) is India’s first 24 hours free emergency phone service for. children in need of assistance.
  2. Special care is given for vulnerable children like those affected by child labour, child marriage and children affected by any abuse.

Samacheer Kalvi 9th Social Science Guide Civics Chapter 3 Human Rights

Question 19.
Where do we find Child Rights in the Indian constitution?
Answer:

  1. Article 24 – No child below the age of 14 must be employed in hazardous employment.
  2. Article 45- Free and compulsory education for all children until they attain the age of 14 years.

Question 20.
Children are the foundation of any nation.
Answer:

  1. Children are the foundation of any nation
  2. When girls get married early, they lose many privileges like childhood happiness, availing education and a healthy life.
  3. The society in turn gets affected by child marriage.
  4. Thus child marriage should be avoided at any cost.

Question 21.
Why is the National Commission for Women a council?
Answer:

  1.  The National Commission for Women (NCW) is constituted in India to review the Constitutional and legal safeguards for women.
  2. It recommends remedial measures and advises the government on all matters of policy affecting the welfare and development of women in the country.

Question 22.
What are Women’s Rights?
Answer:

  1. Women’s Rights are under the Indian Constitution mainly includes equality, dignity and freedom from discrimination.
  2. Additionally, India has various statutes governing the right of women.

Samacheer Kalvi 9th Social Science Guide Civics Chapter 3 Human Rights

Question 23.
Mention about Women Labourers’ Welfare and Dr. B.R.Ambedkar.
Answer:

  1. Dr. B.R. Ambedkar framed many laws for women workers in India.
  2. They are
    • ‘Mines Maternity Benefit Act’,
    • ‘Women Labour Welfare Fund’,
    • ‘Women and Child Labour Protection Act’,
    • ‘Maternity Benefit for Women Labour’,
    • ‘Restoration of Ban on Employment of Women on Underground Work in Coal Mines’.

Question 24.
What are SC and ST Rights?
Answer:

  1. In order to ensure the dignity and security of Adi Dravidars (mostly referred as Scheduled Castes in other States) their rights are ensured.
  2. They remove all forms of exclusion, marginalization, untouchability and discrimination
  3. The Government formulate policies, plans, budgets, schemes and programmes.
  4. This is done to ensure their right to social equity, access to entitlements and right to dignity.
  5. These rights facilitate the betterment of their socio-economic conditions as well as conferring democratic and political rights.

Question 25.
What is RTI?
Answer:

  1. RTI refers to the Right to Information Act.
  2. It is a revolutionary act that aims to promote transparency in the government institutions in India.
  3. This act was enacted in October 2005.
  4. A common man can demand any government organization to provide information.
  5. The information must be provided within thirty days.
  6. If not, a fee will be collected as a penalty from the concerned official.

Question 26.
What are Labour Rights?
Answer:

  1. The Constitution ensures right to equality, equality of opportunity in public employment, right to form associations and unions, right to livelihood.
  2. It prohibits trafficking, forced labour and child labour.
  3. Article 39(d) ensures equal wages to male and female workers for equal work.

V. Answer in detail

Question 1.
What are the functions of SHRC?
Answer:
The functions of SHRC are

  1. The SHRC shall enquire into violation of human rights in respect of matters specified in the state and concurrent lists.
  2. Its objectives and duties are the same as NHRC, but confined only to the state. It has a chairman and two members.
  3. It has the power of a civil court and can take cognizance of cases if received.
  4. It can also recommend compensation to victims.

Samacheer Kalvi 9th Social Science Guide Civics Chapter 3 Human Rights

Question 2.
Democracy, Development and Fundamental Rights can you establish a positive link among these three factors.
Answer:

  1. Democracy has an important role to play in promoting sustainable development.
  2. Free and fair elections, independent media, accountable government as well as other basic democratic principles are all critical components of an environment and conducive to growth.
  3. In a direct democracy, the people decide on the policy initiatives directly.
  4. Democracy is very much responsible and important for the development of a nation.
  5. In a democratic country the citizens are force to express their views and opinions on decisions taken by government.
  6. This makes the government take more responsible decisions and they go with majority people.
  7. All these actions can be carried on with the help of the fundamental rights generated by the constitution of India with legal background.

Question 3.
Explain Child Rights.
Child Rights are,
(a) Right to life:

  1. A child has the right to survive even before its birth.
  2. The right to survival also includes the right to be bom, the right to basic needs of food, shelter and clothing and a dignified living.

(b) Right to the Family environment:

  1. A child has the right to live a normal childhood in a family environment.
  2. Children who have been left destitute, abandoned or orphaned also have the right to live.
  3. These children can be given for adoption to caring families.

(c) Right to benefit from Social security:

  1. Children should get financial support from the country when their parents or guardians are unable to provide them with a good standard of living by themselves, due to any illness, disability or old age.

(d) Right to Education:

  1. Right to Education Act is an Act of the Parliament of India enacted in 2009 for free and compulsory education for children from 6 to 14 years of age as under Article 21A of the Constitution.

(e) Right against sale or trafficking:

  1. Children should be treated as individuals with fundamental human rights.
  2. They are subj ected to sale or trafficking for various reasons like economic exploitation, sexual exploitation, sexual abuse, drug trafficking and child labour.

Samacheer Kalvi 9th Social Science Guide Civics Chapter 3 Human Rights

(f) Right against sexual exploitation:

  1. The state should protect children from sexual exploitation and abuse.
  2. This is done through POCSO Act – Protection of Children from Sexual Offences Act in 2012.

(g) Right against other forms of exploitation like Child labour:

  1. Children are often employed in several industries.
  2. These children are deprived of their childhood, health, and education.

Question 4.
Explain the Right to Information Act (RTI).
Answer:

  1.  The Right to Information Act is a revolutionary act that aims to promote transparency in the government institutions in India.
  2. This act was enacted in October 2005.
  3. A common man can demand any government organization to provide information.
  4. The information must be provided within thirty days.
  5. If not, a fee will be collected as penality from the concerned official
    It is one of the most powerful laws of the country.
  6. This act is people-friendly; even an illiterate person can ask any Public Information Officer to write it down for him.
  7. All government agencies like Municipal Corporations, Government departments, Government Schools, Road Authorities, etc., come under this Act.

Life Skills

Samacheer Kalvi 9th Social Science Guide Civics Chapter 3 Human Rights

Samacheer Kalvi 9th Social Science Guide Geography Chapter 8 Disaster Management: Responding to Disasters

Tamilnadu State Board New Syllabus Samacheer Kalvi 9th Social Science Guide Pdf Geography Chapter 8 Disaster Management: Responding to Disasters Text Book Back Questions and Answers, Important Questions, Notes.

Tamilnadu Samacheer Kalvi 9th Social Science Solutions Geography Chapter 8 Disaster Management: Responding to Disasters

Samacheer Kalvi 9th Social Science Disaster Management: Responding to Disasters Text Book Back Questions and Answers

I. Choose the best answer

Question 1.
One among the following is not the first responder in case of a disaster.
(a) police officers
(b) firefighters
(c) insurance agents
(d) emergency medical technicians
Answer:
(c) insurance agents

Samacheer Kalvi 9th Social Science Guide Geography Chapter 8 Disaster Management: Responding to Disasters

Question 2.
‘Drop, Cover, Hold’ is a mock drill a vowal for
(a) Fire
(b) Earthquake
(c) Tsunami.
(d) Riot
Answer:
(b) Earthquake

Question 3.
When you happen to see a fire break out. You will make a call to
(a) 114
(b) 112
(c) 115
(d) 118
Answer:
(b) 112

Question 4.
Which of the following statements is untrue?
(a) ‘Stop, Drop, Roll’ is for fire.
(b) ‘Drop, Cover, Hold’ is for an earthquake.
(c) ‘If sea water recedes back, run to higher places’ is for flood.
(d) ‘If gunshots are heard, drop to the ground and cover the head with hand’ is for riot.
Answer:
(c) ‘If sea water recedes back, run to higher places’ is for flood.

Question 5.
Which of the following statements belongs to responding to earthquake?
(a) Avoid any place where police or security forces action is in progress.
(b) Know the height of your street above sea level and the distance of your street from the coast.
(c) Stay away from glass, windows, outside doors and walls, and anything that could fall.
(d) Before opening a door, feel it with the back of your hand.
Answer:
(c) Stay away from glass, windows, outside doors and walls, and anything that could fall.

II. Answer in brief

Question 1.
Who are the community’s first responders to disaster?
Answer:
On a daily basis, police officers, firefighters, and emergency medical technicians are our community’s first responders, whether during fire, flood or acts of terrorism.

Samacheer Kalvi 9th Social Science Guide Geography Chapter 8 Disaster Management: Responding to Disasters

Question 2.
What are the four phases of the Disaster Management Cycle?
Answer:
The four phases of the disaster management cycle.

  1. Mitigation
  2. Preparedness
  3. Response
  4. Recovery

Samacheer Kalvi 9th Social Science Guide Geography Chapter 8 Disaster Management Responding to Disasters

Question 3.
Though Japan has the densest seismic network, Indonesia has the most number of earthquakes. Why?
Answer:
Japan is in a very active seismic area and it has the densest seismic network in the world.
Indonesia is in a very active seismic zone, but because it is larger than Japan, it has more earthquakes.

Samacheer Kalvi 9th Social Science Guide Geography Chapter 8 Disaster Management: Responding to Disasters

Question 4.
How many males and females die per day due to fire in India?

  1. On average, in India, every year, about 25,000 persons die due to fires and related causes.
  2. Female accounts for about 66% of those killed in fire accidents.
  3. It is estimated that about 42 females and 21 males die every day in India due to fire.

Question 5.
What should you do after a Tsunami?
Answer:

  1. You should continue using a weather radio or staying tuned to a Coast Guard emergency frequency station or a local radio or television station for updated emergency information.
  2. Check yourself for injuries and get first aid if necessary, before helping injured or trapped persons.
  3. If someone needs to be rescued, call professionals with the right equipment to help.
  4. Help people who require special assistance, like Infants, elderly people, those without transportation, large families who may need additional help in an emergency situation, people with disabilities, and the people who care for them.
  5. Stay out of a building if water remains around it. Tsunami water, like floodwater, can undermine foundations, causing buildings to sink, floors to crack, or walls to collapse.
  6. Check for gas leaks. If you smell gas or hear a blowing or hissing noise, open a window and get everyone outside quickly.

III. Answer in Paragraph.

Question 1.
Write a short note on Tsunami.
Answer:
A tsunami can kill or injure people and damage or destroy buildings and infrastructure as waves come forth and recede. A tsunami is a series of enormous ocean waves caused by earthquakes, underwater landslides, volcanic eruptions or asteroids. Tsunamis can travel 700-800 km per hour, with waves 10-30 meters high. It causes flooding and disrupts transportation, power, communications, and water supply.

Samacheer Kalvi 9th Social Science Guide Geography Chapter 8 Disaster Management: Responding to Disasters

Question 2.
What do you do if you are indoors during an earthquake?
Answer:
During an earthquake, if you are indoor:

  1. DROP to the ground; take COVER by getting under a sturdy table or another piece of furniture and HOLD ON until the shaking stops. If there is no table or desk near you, cover your face and head with your arms and crouch in an inside comer of the building.
  2. Protect yourself by staying under the lintel of an inner door, in the comer of a room, under a table, or even under a bed.
  3. Stay away from glass windows outside doors and walls, and anything that could fall, (such as lighting fixtures or furniture).
  4. Stay inside until the shaking stops and afterward it is safe to go outside.

Question 3.
How do you respond to Tsunami?
Answer:

  1. You should find out if your home, school, workplace or other frequently visited locations are in tsunami hazard areas along the sea-shore.
  2. Plan evacuation routes from your home, school, workplace, or any other place you could be, where tsunamis poses a risk.
  3. Use a weather radio or stay tuned to a local radio or television station to keep informed of local watches and warnings.
  4. Discuss tsunamis with your family. Everyone should be aware of what to do when a tsunami strikes. Discussing tsunamis ahead of time will help reduce fear and save precious time in an emergency. Review flood safety and precautionary measures with your family.

Samacheer Kalvi 9th Social Science Guide Geography Chapter 8 Disaster Management: Responding to Disasters

Question 4.
Write three sentences about what to do during a fire.
Answer:

  1. Evacuate calmly and quickly whenever a fire alarm or carbon monoxide alarm sounds.
  2. Before opening the door, feel it with the back of your hand. If the door is hot, do not open it.
  3. If you encounter smoke during your evacuation, stay low to the floor.
  4. Know the locations of fire extinguishers, fire alarm pull stations, and exits.

Intext Hots

Question 1.
Why should you cut off all the branches of trees below 3 meters of height standing near your house?
Answer:

  1. Large trees, up to 70 feet or more should be planted at least 20 feet from the home, medium-sized trees up to 70 feet tall, 15 feet from the home, and small trees 30 feet tall or less, 8 to 10 feet from the home.
  2. If the branches and limbs extend part the propriety line trimming and cutting up to the property line allowed.

Samacheer Kalvi 9th Social Science Disaster Management: Responding to Disasters Additional Important Questions and Answers

I. Choose the best answer

Question 1.
Find out the correct statements.
(a) The place on the earth’s surface above the focus is epicenter.
(b) During an earthquake, be chosen to building
(c) Stay inside until the shaking stops.
(d) Fire causes injuring to people and animals.
Answer:
(c) Stay inside until the shaking stops and d. Fire causes injuring to people and animals.

Samacheer Kalvi 9th Social Science Guide Geography Chapter 8 Disaster Management: Responding to Disasters

Question 2.
Match the following:

  1. Firefighters – (i) 10 – 30 mt high
  2. Seismograph – (ii) Respiratory hazard
  3. Tsunami – (iii) Forests
  4. Smoke – (iv) First responder
  5. Wild Fire – (v) Earthquake

Answer:

  1. – (iv)
  2. – (v)
  3. – (i)
  4. – (ii)
  5. – (iii)

II. Very short answer

Question 1.
What is a disaster?
Answer:
A disaster is “a catastrophe that causes great damage or loss of life and property”.

Question 2.
What is meant by stop, drop, and roll?
Answer:

  1. To escape a fire, stop, drop, and roll.
  2. In case your clothes bum, stop running, drop on the floor, and roll to stop fire from spreading.

III. Short answer

Question 1.
What do you mean by Disaster Response?
Answer:
Disaster response entails restoring physical facilities, rehabilitation of affected population, restoration of lost livelihoods and reconstruction efforts to restore the infrastructure lost or damaged. The Response Phase focuses primarily on emergency relief: saving lives, providing first aid, restoring damaged systems (communications and transportation), meeting the basic life requirements of those impacted by disaster (food, water and shelter) and providing mental health and spiritual support and care.

Question 2.
How is the Earthquake caused?
Answer:

  1. Earthquake is a sudden vibration of the part of the earth caused by plate movements.
  2. It occurs along the plate boundaries.
  3. The place inside the earth where an earthquake originates is the focus.
  4. The point on the earth’s surface above the focus is epicenter.
  5. The damage caused by the earthquake is the highest near the epicenter.
  6. The earthquake is measured by an instrument is called Seismograph.
  7. It is recorded on the Richter scale.

Samacheer Kalvi 9th Social Science Guide Geography Chapter 8 Disaster Management: Responding to Disasters

Question 3.
What is to be done after a Tsunami?
Answer:

  1. You should continue using a Weather Radio or staying tuned to a Coast Guard emergency frequency station or a local radio or television station for updated emergency information.
  2. Check yourself for injuries and get first aid if necessary before helping the injured or trapped.
  3. If someone needs to be rescued, call professionals with the right equipment to help.
  4. Help people who require special assistance Infants, elderly people, those without transportation, large families who may need additional help in an emergency situation, people with disabilities, and the people who care for them.
  5. Stay out of a building if water remains around it. Tsunami water, like floodwater, can undermine foundations, causing buildings to sink, floors to crack, or walls to collapse.
  6. Check for gas leaks. If you smell gas or hear a blowing or hissing noise, open a window and get everyone outside quickly.

Question 4.
Write about Fire Safety Do’s and Don’ts.
Answer:
Fire Safety Do’s and Don’ts

  1. Know your building’s evacuation plan.
  2. Evacuate calmly and quickly, whenever a fire alarm or carbon monoxide alarm sounds.
  3. Before opening a door, feel it with the back of your hand. If the door is hot, do not open it.
  4. If you encounter smoke during your evacuation, stay low to the floor.
  5. Know the outside rally point for your building.
  6. Know the locations of fire extinguishers, fire alarm pull stations, and exits.

Samacheer Kalvi 9th Social Science Guide Geography Chapter 8 Disaster Management: Responding to Disasters

Question 5.
What should be done during a fire?
Answer:

  1. Stay calm.
  2. Pull the nearest fire alarm or call 112.
  3. Give your name and the location of the fire. Do not hang up until the police dispatcher tells you to do so.
  4. Leave the building immediately.
  5. Inform others as you pass them to leave the building immediately.
  6. Walk – don’t run – to the nearest exit.
  7. Never use elevators – an elevator may become a trap.

IV. Answer in one or two sentences

Question 1.
Why do you think you should cover your head with one hand and hold the table with the other hands during an earthquake?
Answer:
it is mainly to protect the head and neck from gently damaged.

Question 2.
During an earthquake, why should we exit through the staircase and not use elevators?
Answer:
Because the earthquake likely to knock out electrical power, the elevator machinery will not work.

Question 3.
Suppose you are in a room of a strong building without any furniture when an earthquake occurs. What would you do to protect yourself from the earthquake?
Answer:
if doors are opened, stand under a doorway or in a comer inside the room. Cover your face and head with your arms.

Samacheer Kalvi 9th Social Science Guide Geography Chapter 8 Disaster Management: Responding to Disasters

Question 4.
Reason out why should you stay away from buildings with glass panes during an earthquake.
Answer:
At jolting of the earthquake bursting and breaking of the wall, glass panes may happen. So it is better to be away from it.