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Tamilnadu State Board New Syllabus Samacheer Kalvi 11th Maths Guide Pdf Chapter 2 Basic Algebra Ex 2.11 Text Book Back Questions and Answers, Notes.

Tamilnadu Samacheer Kalvi 11th Maths Solutions Chapter 2 Basic Algebra Ex 2.11

Question 1.
Simplify
(a) (125)^2/3
(b) 16^-3/4
(c) (- 1000)^-2/3
(d) (3^-6)^1/3
(e) \(\frac{27^{-\frac{2}{3}}}{27^{-\frac{1}{3}}}\)
Answer:
(a) (125)^2/3

(b) 16^-3/4

(c) (- 1000)^-2/3

(d) (3^-6)^1/3

(e) \(\frac{27^{-\frac{2}{3}}}{27^{-\frac{1}{3}}}\)

Question 2.
Evaluate
Answer:

Question 3.
If \(\left(x^{\frac{1}{2}}+x^{-\frac{1}{2}}\right)^{2}=\frac{9}{2}\) then find the value of \(\left(x^{\frac{1}{2}}-x^{-\frac{1}{2}}\right)\) for x > 1
Answer:

Question 4.
Simplify and hence find the value of n:
\(\frac{3^{2 n} \cdot 9^{2} \cdot 3^{-n}}{3^{3 n}}\) = 27
Answer:
Given

4 – 2n = 3
2n = 4 – 3
2n = 1
n = \(\frac { 1 }{ 2 }\)

Question 5.
Find the radius of the spherical tank whose volume is \(\frac{32 \pi}{3}\) units.
Answer:
Let r be the radius of the spherical tank.
Given volume of the spherical tank = \(\frac{32 \pi}{3}\)
\(\frac{4}{3}\)πr³ = \(\frac{32 \pi}{3}\)
4r³ = 32
r³ = \(\frac{32}{4}\) = 8
r³ = 2³
r = 2
∴ Radius of the spherical tank r = 2 units.

Question 6.
Simplify by rationalizing the denominator \(\frac{7+\sqrt{6}}{3-\sqrt{2}}\)
Answer:
\(\frac{7+\sqrt{6}}{3-\sqrt{2}}\)
Multiply the numerator and denominator by 3 + √2

Question 7.
Simplify:

Answer:

Question 8.
If x = √2 + √3 find \(\frac{x^{2}+1}{x^{2}-2}\)
Answer:

Tamilnadu State Board New Syllabus Samacheer Kalvi 11th Maths Guide Pdf Chapter 2 Basic Algebra Ex 2.10 Text Book Back Questions and Answers, Notes.

Tamilnadu Samacheer Kalvi 11th Maths Solutions Chapter 2 Basic Algebra Ex 2.10

Determine the region in the plane determined by the inequalities

Question 1.
x ≤ 3y, x ≥ y
Answer:
Consider the line x = 3y
When y = 0 ⇒ x = 0
When y = 1 ⇒ x = 3
When y = – 1 ⇒ x = – 3

Consider the line x = y
When x = 0 ⇒ y = o
When x = 1 ⇒ y = 1
When x = – 1 ⇒ y = – 1

To find the region of x ≤ 3y: The line x = 3y divides the cartesian plane into two half planes. Consider the point (1,1) this point satisfies the inequality x < 3y. This point (1,1) lies above the line x = 3y.

Hence all points satisfying the inequality lie above the line x = 3y.

Therefore x < 3y represents the upper half plane of the Cartesian plane bounded by the line x = 3y. Since x ≤ 3y, this region also contains all the points on the straight line x = 3y.

To find the region x ≥ y: The line x = y divides the cartesian plane into two half planes. Consider the point (2,1). This point (2,1) satisfies the inequality x > y and this point (2,1) lies below the line x = y. ∴ All points satisfying the inequality x > y will lie below the line x = y. Therefore x > y represents the lower half plane of the cartesian plane bounded by the line x = y. Since x > y this region also contains all the points on the straight line x = y.

The required region is the region common to the regions x ≤ 3y and x ≥ y

Question 2.
y ≥ 2x, – 2x + 3y ≤ 6
Answer:
Consider the straight line y = 2x
When x = 0 ⇒ y = 2 × 0 = 0
When x = 0 ⇒ y = 2 × 1 = 2
When x = – 1 ⇒ y = 2 × – 1 = – 2

Consider the line – 2x + 3y = 6
When x = 0 ⇒ – 2 × 0 + 3y = 6 ⇒ 3y = 6 ⇒ y = 2
When y = 0 ⇒ – 2x + 3 × 0 = 6 ⇒ -2x = 6 ⇒ x = – 3

To find the region of y ≥ 2x: The straight line y = 2x divides the cartesian plane into two half planes. Consider the point (1, 3) satisfying the inequality y > 2x. This point (1, 3) lies above the straight line y = 2x. ∴ All points satisfying the inequality y > 2x will lie above the line y = 2x.

To find the region of -2x + 3y ≤ 6:
The straight line – 2x + 3y = 6 divides the cartesian plane into two half planes one half plane contains the origin and the other half plane does not contain the origin.

Substitute the origin (0, 0) in the inequality – 2x + 3y < 6
we get – 2 × 0 + 3 × 0 < 6 ⇒ 0 < 6
∴ (0,0) satisfies the inequality – 2x + 3y < 6
∴ The inequality – 2x + 3y < 6 represents the half plane containing the origin. Since – 2x + 3y ≤ 6, this region contains all the points on the straight line – 2x + 3y = 6.

The required region is the region common to y ≥ 2x and – 2x + 3y ≤ 6

Question 3.
3x + 5y ≥ 45, x ≥ 0, y ≥ 0
Answer:
Consider the line 3x + 5y = 45
when x = 0, 3 × 0 + 5y = 45 ⇒ y = \(\frac{45}{5}\) = 9
when y = 0, 3x + 5 × 0 = 45 ⇒ x = \(\frac{45}{3}\) = 15

To find the region of x ≥ 0, y ≥ 0:
x ≥ 0 and y ≥ 0 denote the first quadrant of the Cartesian plane.
Since x ≥ 0 and y ≥ 0 this region contains all the points on the lines x = 0 and y = 0.

To find the region of 3x + 5y ≥ 45: The straight-line 3x + 5y = 45 divides the cartesian plane into two half-planes, one-half plane containing the origin and the other half-plane does not contain the origin.

Substitute the origin (0,0) in the inequality 3x + 5y > 45 we get 3 × 0 + 5 × 0 > 45 ⇒ 0 > 45 which is impossible. Therefore, (0, 0) does not satisfy the inequality 3x + 5y > 45 represents the half plane that does not contain the origin bounded by the straight line 3x + 5y = 45. Since 3x + 5y ≥ 45, x ≥ 0, y ≥ 0, this region contains all the points on the straight lines 3x + 5y = 45.

∴ The required region is the common region bounded by x ≥ 0, y ≥ 0, and 3x + 5y ≥ 45.

Question 4.
2x + 3y ≤ 35, y ≥ 2, x ≥ 5.
Answer:
Consider the straight line 2x + 3y = 35
When x = 0, 2 × 0 + 3y = 35 ⇒ \(\frac{35}{3}\)
When y = 0, 2x + 3 × 0 = 35 ⇒ \(\frac{35}{2}\)

To find the region of 2x + 3y ≤ 35: The straight-line 2x + 3y = 35 divides the cartesian plane into two half-planes, one-half plane contains the origin and the other half-plane does not contain the origin.

Substitute the origin (0, 0) in the inequality 2x + 3y < 35, we get 2 × 0 + 3 × 0 < 35 ⇒ 0 < 35. (0, 0) satisfies the inequality.

Therefore, the inequality 2x + 3y < 35 represents the half plane that contains the origin (0, 0) bounded by the straight line 2x + 3y = 35. Since 2x + 3y ≤ 35, this region contains all the points on the straight line 2x + 3y = 35.

To find the region y ≥ 2: The straight line y = 2 divides the cartesian plane into two half-planes, one-half plane contains the origin and the other half-plane does not contain the origin. Substitute the point (0, 0) in the inequality y ≥ 2 we get 0 >2 which is impossible. Hence (0, 0) does not satisfy the inequality y > 2.

∴ The inequality y > 2 represents the half-plane that does not contain the origin bounded by the straight line y = 2. Since y ≥ 2, this region contains all the points on the straight line y = 2.

To find the region x ≥ 5: The straight line x – 5 divides the cartesian plane into two half-planes, one half-plane containing the origin and the other half-plane does not contain the origin.

Substitute the origin (0,0) in the inequality x > 5 we get 0 > 5 which is impossible. Hence (0, 0) does not satisfy the inequality x > 5.

∴ The inequality x > 5 represents the half-plane that does not contain the origin bounded the straight line x = 5.
Since x ≥ 5, this region contains all the points on the straight line x = 5

∴ The required region is the common region bounded by 2x + 3y ≤ 35, y ≥ 2, x ≥ 5.

Question 5.
2x + 3y ≤ 6, x + 4y ≤ 4, x ≥ 0, y ≥ 0
Answer:
Consider the straight line 2x + 3y = 6
When x = 0, 2 × 0 + 3y = 6 ⇒ y = \(\frac{6}{3}\) = 2
When y = 0, 2x + 3 × 0 = 6 ⇒ x = \(\frac{6}{2}\) = 3

Consider the straight line x + 4y = 4
When x = 0 ⇒ 0 + 4y = 4 ⇒ y = \(\frac{4}{4}\) = 1
When y = 0 ⇒ x + 4 × 0 = 4 ⇒ x = 4

To find the region of 2x + 3y ≤ 6: The straight line 2x + 3y = 6 divides the cartesian plane into two half planes, one half plane contains the origin and the other half plane does not contain the origin. Substitute the origin (0, 0) in the inequality 2x + 3y < 6 we get 2 × 0 + 3 × 0 < 6 ⇒ 0 < 6

∴ The origin (0,0) satisfies the inequality 2x + 3y < 6. Hence the inequality 2x + 3y < 6 represents the half plane that contains the origin (0, 0). Since 2x + 3y ≤ 6, this region contains all the points on the straight line 2x + 3y = 6.

To find the region of x + 4y ≤ 4 : The straight line x + 4y = 4 divides the cartesian plane into two half planes, one half plane contains the origin and the other half plane does not contain the origin. Substitute the origin (0, 0) in the inequality x + 4y < 4, we get 0 + 4 × 0 < 4 ⇒ 0 < 4.

Therefore the origin (0, 0) satisfies the inequality x + 4y < 4. Therefore the inequality x + 4y < 4 represents the half-plane that contains the origin bounded by the line x + 4y = 4. Since x + 4y ≤ 4, this region contains all the points on the straight line.

To find the region x ≥ 0, y ≥ 0: x ≥ 0 and y ≥ 0 denote the first quadrant of the cartesian plane.
Since x ≥ 0 and y ≥ 0 this region contains all the points on the lines x = 0 and y = 0.

The required region is the common region bounded by 2x + 3y ≤ 6, x + 4y ≤ 4, x ≥ 0 and y ≥ 0.

Question 6.
x – 2y ≥ 0 , 2x – y ≤ – 2 , x ≥ 0, y ≥ 0
Answer:
Consider the straight line x – 2y = 0
When x = 0
⇒ -2y = 0
⇒ y = 0

When x = 2
⇒ 2 – 2y = 0
⇒ 2y = 2
⇒ y = 1

When x = -2
⇒ – 2 – 2y = 0
⇒ -2y = 2
⇒ y = – 1

Consider the line 2x – y = – 2
When x = 0 ⇒ – y = – 2 ⇒ y = 2
When y = 0 ⇒ 2x – 0 = – 2 ⇒ x = – 1

To find the region of x – 2y ≥ 0: The straight line x – 2y = 0 divides the cartesian plane into two half-planes. Consider the point (3,1) satisfying the inequality x > 2y. The point (3, 1) lies below the straight line x = 2y in the cartesian plane.

∴ All the points satisfying the inequality x > 2y will lie in the half-plane below the straight line x = 2y. Since x ≥ 2y this region contains all the points on the straight line x = 2y.

To find the region of 2x – y ≤ – 2:
-(2x – y) ≥ 2 ⇒ – 2x + y ≥ 2
Consider the straight line – 2x + y = 2. This line divides the cartesian plane in to two half planes, one half plane contains the origin and the other half plane does not contain the origin. Substitute the origin (0, 0) in the inequality – 2x + y > 2 we get- 2 × 0 + 0 > 2 ⇒ 0 > 2 which is impossible. Therefore (0, 0) does not satisfy the inequality -2x + y > 2. Hence the inequality -2x + y > 2 represents the half plane that does not contain the origin bounded by the straight line. Since -2x + y > 2, this region contains all the points on the straight line -2x + y = 2

To find the region of x ≥ 0, y ≥ 0: x ≥ 0 and y ≥ 0 denote the first quadrant of the cartesian plane. Since x ≥ 0 and y ≥ 0 this region contains all the points on the lines x = 0 and y = 0.

∴ The required region is the region common to x – 2y ≥ 0 , 2x – y ≤ – 2 , x ≥ 0, y ≥ 0.

Question 7.
2x + y ≥ 8, x + 2y ≥ 8, x + y ≤ 6
Answer:
Consider the straight line 2x + y = 8
When x = 0 ⇒ 2 × 0 + y = 8 ⇒ y = 8
When y = 0 ⇒ 2x + 0 = 8 ⇒ x = \(\frac{8}{2}\) = 4

Consider the straight line x + 2y = 8
When x = 0 ⇒ 0 + 2y = 8 ⇒ y = \(\frac{8}{2}\) = 4
When y = 0 ⇒ x + 2 × 0 = 8 ⇒ x = 8

Consider the straight line x + y = 6
When x = 0 ⇒ 0 + y = 6 ⇒ y = 6
When y = 0 ⇒ x + 0 = 6 ⇒ x = 6

To find the region of 2x + y ≥ 8: The straight-line 2x + y = 8 divides the cartesian plane into two half-planes one half plane contains the origin and the other half plane does not contain the origin. Substitute the origin (0, 0) in the inequality 2x + y > 8 we get 2 × 0 + 0 > 8 ⇒ 0 > 8 which is impossible.
∴ The origin (0, 0) does not satisfy the inequality 2x + y > 8. Hence the inequality 2x + y > 8 represents the half plane that does not contain the origin bounded by the straight line 2x + y = 8. Since 2x + y ≥ 8, this region contains all the points on the straight line 2x + y = 8.

To find the region of x + 2y ≥ 8: The straight line x + 2y = 8 divides the cartesian plane into two half planes, one half plane contains the origin and the other half plane doesnot contain the origin. Substitute the origin (0, 0) in the inequality x + 2y > 8 we get 0 + 2 × 0 > 8 ⇒ 0 > 8 which is impossible. ∴ The origin (0, 0) does not satisfy the inequality x + 2y > 8. Therefore, the inequality x + 2y > 8 represents the half plane that does not contain the origin bounded by the straight line x + 2y = 8. Since x + 2y ≥ 8 this region contains all the points on the straight line x + 2y = 8.

To find the region of x + y ≤ 6: The straight line x + y = 6 divides the cartesian plane into two half-planes, one half-plane contains the origin and the other half-plane does not contain the origin. Substitute the origin (0, 0) in the inequality x + y < 6 we get 0 + 0 < 6 ⇒ 0 < 6 which is true.
∴ The origin (0, 0) satisfies the inequality x + y < 6. Hence, the inequality x + y < 6 represents the half plane that contains the origin bounded by the straight line x + y = 6. Since x + y ≤ 6, this region contains all the points on the straight line x + y = 6.

Thus the required region is the region common to 2x + y ≥ 8, x + 2y ≥ 8, x + y ≤ 6

Tamilnadu State Board New Syllabus Samacheer Kalvi 11th Maths Guide Pdf Chapter 2 Basic Algebra Ex 2.8 Text Book Back Questions and Answers, Notes.

Tamilnadu Samacheer Kalvi 11th Maths Solutions Chapter 2 Basic Algebra Ex 2.8

Question 1.
Find all values of x for which \(\frac{x^{3}(x-1)}{x-2}\) > 0
Answer:
The given inequality is f(x) = \(\frac{x^{3}(x-1)}{x-2}\) > 0
[The critical numbers of f(x) are those values of x for which f(x) = 0, and those values of x for which f(x) is not defined.
When x = 2 , f(x) = ∞ ⇒ f(x) is not defined.]
The critical numbers are x = 0, 1, 2
Divide the number line into 4 intervals
(- ∞, 0), (0, 1), (1, 2) and (2, ∞)

(1) (- ∞, 0)
When x < 0 say x = – 1
The factor x³ = (- 1)³ = – 1 < 0
The factor x – 1 = – 1 – 1 = – 2 < 0
The factor x – 2 = – 1 – 2 = – 3 < 0
∴ \(\frac{x^{3}(x-1)}{x-2}\) < 0
Thus \(\frac{x^{3}(x-1)}{x-2}\) > 0 is not true in the interval (- ∞, 0)
Therefore, it has no solution in the interval (- ∞, 0)

(2) (0, 1)
When 0 < x < 1 say x = 0.5
The factor x³ = (0.5 )³ > 0
The factor x – 1 = 0.5 – 1 = – 0.5 < 0
The factor x – 2 = 0.5 – 2 = – 1.5 < 0
Thus x³ > 0, x – 1 < 0 and x – 2 < 0
∴ \(\frac{x^{3}(x-1)}{x-2}\) > 0
Thus \(\frac{x^{3}(x-1)}{x-2}\) > 0 is true in the interval (0, 1)
Therefore it has solution in (0,1)

(3) (1, 2)
When 1 < x < 2 say x = 1.5
The factor x³ = 0
The factor x – 1 = 1.5 – 1 = 0.5 > 0
The factor x – 2 = 1.5 – 2 = – 0.5 < 0
Thus x³ > 0, x – 1 > 0 and x – 2 < 0
∴ \(\frac{x^{3}(x-1)}{x-2}\) < 0
Thus \(\frac{x^{3}(x-1)}{x-2}\) > 0 is not true in the interval (1, 2).
Therefore it has no solution in (1, 2).

(4) (2, ∞)
When x > 2 say x = 3
The factor x³ = 3³ > 0
The factor x – 1 = 3 – 1 = 2 > 0
The factor x – 2 = 3 – 2 = 1 > 0
Thus x³ > 0, x – 1 > 0 and x – 2 > 0
∴ \(\frac{x^{3}(x-1)}{x-2}\) > 0
Thus \(\frac{x^{3}(x-1)}{x-2}\) > 0 is true in the interval (2, ∞).
Therefore it has a solution in (2, ∞)

∴ \(\frac{x^{3}(x-1)}{x-2}\) > 0 has solution in the intervals (0, 1) and (2, ∞)
∴ The solution set is given by (0, 1) ∪ (2, ∞)

Question 2.
Find all values of x that satisfies the inequality \(\frac{2 x-3}{(x-2)(x-4)}\) < 0.
Answer:
The given inequality is

[The critical numbers of f(x) are those values of x for which f(x) = 0, and those values of x for which f(x) is not defined. When x = 2, f(x) = ∞ ⇒ f(x) is not defined.]
The critical numbers are x = \(\frac{3}{2}\), x = 2 , x = 4
Divide the number into 4 intervals

(1) \(\left(-\infty, \frac{3}{2}\right)\)
When x < \(\frac{3}{2}\) say x = 0
The factor x – \(\frac{3}{2}\) = 0 – \(\frac{3}{2}\) < 0
The factor x – 2 = 0 – 2 < 0
The factor x – 4 = 0 – 4 < 0
Thus x – \(\frac{3}{2}\) < 0, x – 2 < 0 and x – 4 < 0

(2) \(\left(\frac{3}{2}, 2\right)\)

(3) (2, 4)
When 2 < x < 4 say x = 3 The factor x – \(\frac{3}{2}\) = 3 – \(\frac{3}{2}\) = \(\frac{3}{2}\) > 0
The factor x – 2 = 3 – 2 = 1 > 0
The factor x – 4 = 3 – 4 = – 1 < 0 Thus x – \(\frac{3}{2}\) > 0, x – 2 > 0 and x – 4 < 0

Thus \(\frac{2 x-3}{(x-2)(x-4)}\) < 0 is true in the interval (2, 4) ∴ It has solution in (2, 4). (4) (4, ∞) When x > 4 say x = 5
The factor x – \(\frac{3}{2}\) = 5 – \(\frac{3}{2}\) = \(\frac{7}{2}\) > 0
The factor x – 2 = 5 – 2 = 3 >0
The factor x – 4 = 5 – 4 = 1 > 0
Thus x – \(\frac{3}{2}\) > 0, x – 2 > 0 and x – 4 > 0

Thus \(\frac{2 x-3}{(x-2)(x-4)}\) < 0 is not true in the interval (4, ∞)
∴ It has a solution in (4, ∞)

Question 3.
Solve: \(\frac{x^{2}-4}{x^{2}+4 x-15}\) ≤ 0
Answer:

[The critical numbers of f(x) are those values of x for which f(x) = 0, and those values of x for which f(x) is not defined. When x = – 3, 5. f(x) = ∞ ⇒ f(x) is not defined.]

The critical numbers are x = – 2 , 2, – 3, 5
Divide the number line into five intervals
(- ∞, – 3), (- 3, – 2), (- 2, 2), (2, 5) ,(5, ∞)

(a) (- ∞, – 3)
When x <- 3 say x = – 4
The factor x + 2 = – 4 + 2 = – 2 < 0
The factor x – 2 = – 4 – 2 = 6 < 0
The factor x + 3 = – 4 + 3 = – 1 < 0
The factor x – 5 = – 4 – 5 = – 9 < 0
Thus x + 2 < 0, x + 3 < 0, x – 2 < 0, x – 5 < 0
∴ \(\frac{x^{2}-4}{x^{2}+4 x-15}\) > 0
Thus \(\frac{x^{2}-4}{x^{2}+4 x-15}\) ≤ 0 is not true in the interval (- ∞, – 3).
∴ It has no solution in (- ∞, – 3)

(b) (- 3, – 2)
When – 3 < x ≤ – 2 say x = – 2.5
The factor x + 2 = – 2.5 + 2 = – 0.5 < 0
The factor x – 2 = – 2.5 – 2 = – 4.5 < 0 The factor x + 3 = – 2.5 + 3 = 0.5 > 0
The factor x – 5 = – 2.5 – 5 = – 7.5 < 0
Thus x + 2 < 0, x + 3 > 0
and
x – 2 < 0
x – 5 < 0
∴ \(\frac{x^{2}-4}{x^{2}+4 x-15}\) < 0
Thus \(\frac{x^{2}-4}{x^{2}+4 x-15}\) ≤ 0 is not true in the interval (- 3, – 2).
∴ It has no solution in (- 3, – 2)

(c) (-2, 2)
When – 2 ≤ x ≤ 2 say x = 0
The factor x + 2 = 0 + 2 = 2 > 0
The factor x – 2 = 0 – 2 = – 2 < 0
The factor x + 3 = 0 + 3 = 3 > 0
The factor x – 5 = 0 – 5 = – 5 < 0

Thus x + 2 > 0 ,
x + 3 > 0
and
x – 2 < 0
x – 5 < 0
∴ \(\frac{x^{2}-4}{x^{2}+4 x-15}\) > 0
Thus \(\frac{x^{2}-4}{x^{2}+4 x-15}\) ≤ 0 is not true in the interval (- 2, – 2).
∴ It has no solution in (- 2, – 2)

(d) (2, 5)
When 2 ≤ x < 5 say x = 3 The factor x + 2 = 3 = 3 + 2 = 5 > 0
The factor x – 2 = 3 – 2 = 1 > 0
The factor x + 3 = 3 + 3 = 6 > 0
The factor x – 5 = 3 – 5 = – 2 < 0 Thus x + 2 > 0,
x + 3 > 0
and
x – 2 > 0
x – 5 < 0
∴ \(\frac{x^{2}-4}{x^{2}+4 x-15}\) < 0
Thus \(\frac{x^{2}-4}{x^{2}+4 x-15}\) ≤ 0 is not true in the interval (2, 5).
∴ It has no solution in (2, 5)

(e) (5, ∞)
When 5 < x < ∞ say x = 6 The factor x + 2 = 6 + 2 = 8 > 0
The factor x – 2 = 6 – 2 = 4 > 0
The factor x + 3 = 6 + 3 = 9 > 0
The factor x – 5 = 6 – 5 = 1 > 0
Thus
x + 2 > 0,
x + 3 > 0
and
x – 2 > 0,
x – 5 > 0
∴ \(\frac{x^{2}-4}{x^{2}+4 x-15}\) > 0
Thus \(\frac{x^{2}-4}{x^{2}+4 x-15}\) ≤ 0 is not true in the interval (5, ∞).
∴ It has no solution in (5, ∞)
The given inequality f(x) = \(\frac{x^{2}-4}{x^{2}+4 x-15}\) ≤ 0 has solution in the intervals (-3, – 2]
∴ The solution set is (-3, 2] ∪ [2, 5)

Tamilnadu State Board New Syllabus Samacheer Kalvi 11th Maths Guide Pdf Chapter 2 Basic Algebra Ex 2.7 Text Book Back Questions and Answers, Notes.

Tamilnadu Samacheer Kalvi 11th Maths Solutions Chapter 2 Basic Algebra Ex 2.7

Question 1.
Factorize x⁴ + 1
Answer:
The given equation is x⁴ + 1
x⁴ + 1 = (x²)² + 1²
= (x² + 1)² – 2 (x²) (1)
[ a² + b² = (a + b)² – 2ab]
= (x² + 1)² – (√2x)²
= (x² + 1 + √2x) (x² + 1 – √2x)
x⁴ + 1 = (x² + 2x + 1) (x² – √2x + 1)

Question 2.
If x⁴ + x + 1 is a factor of the polynomial 3x³ + 8x² + 8x + a, then find the value of a.
Answer:
Given that x² + x + 1 is a factor of the polynomial 3x³ + 8x² + 8x + a.
∴ 3x³ + 8x² + 8x + a is divisible by x² + x + 1

Since 3x³ + 8x² + 8x + a is divisible by x² + x + 1, the remainder must be zero.
a – 5 = 0
⇒ a = 5

Tamilnadu State Board New Syllabus Samacheer Kalvi 11th Maths Guide Pdf Chapter 2 Basic Algebra Ex 2.6 Text Book Back Questions and Answers, Notes.

Tamilnadu Samacheer Kalvi 11th Maths Solutions Chapter 2 Basic Algebra Ex 2.6

Question 1.
Find the zeros of the polynomial function f(x) = 4x² – 25
Answer:
Given f(x) = 4x² – 25
To find the zeors of f(x), put f(x) = 0
∴ 4x² – 25 = 0
⇒ 4x² = 25
⇒ x² = \(\frac{25}{4}\)
⇒ x = ±\(\sqrt{\frac{25}{4}}\) = ±\(\frac{5}{2}\)
Hence the zeros of f(x) are \(-\frac{5}{2}, \frac{5}{2}\)

Question 2.
If x = – 2 is one root of x³ – x² – 17x = 22, then find the other roots of equation.
Answer:
Let f(x) = x³ – x² – 17x – 22 = 0 —– (1)
Given that x = – 2 is a root of f(x).
∴ x + 2 is a factor of f (x)
Using synthetic division

Comparing equation (1) with the equation ax² + bx + c = 0 we have
a = 1, b = – 3 , c = – 11

Question 3.
Find the real roots of x⁴ = 16.
Answer:
x⁴ = 16
⇒ x⁴ – 16 = 0
(i.e.,) x⁴ – 4² = 0
⇒ (x² + 4)(x² – 4) = 0
x² + 4 = 0 will have no real roots
so solving x² – 4 = 0
x² = 4

Question 4.
Solve (2x + 1)² – (3x + 2)² = 0
Answer:
The given equation is (2x + 1)² (3x + 2)² = 0
(2x + 1 + 3x + 2) [(2x + 1) – (3x + 2)] = 0
[a² – b² = (a + b) (a – b)]
(5x + 3) (2x + 1 – 3x – 2) = 0
(5x + 3)(- x – 1) = 0
– (5x + 3)(x + 1) = 0
5x + 3 = 0 or x + 1 = 0
x = – \(\frac{3}{5}\) or x = – 1
∴ Solution set is { – 1, \(\frac{3}{5}\)}

Tamilnadu State Board New Syllabus Samacheer Kalvi 11th Maths Guide Pdf Chapter 2 Basic Algebra Ex 2.4 Text Book Back Questions and Answers, Notes.

Tamilnadu Samacheer Kalvi 11th Maths Solutions Chapter 2 Basic Algebra Ex 2.4

Question 1.
Construct a quadratic equation with roots 7 and – 3.
Answer:
The given roots are 7 and -3
Let α = 7 and β = -3
α + β = 7 – 3 = 4
αβ = (7)(-3) = -21
The quadratic equation with roots α and β is x² – (α + β) x + αβ = 0
So the required quadratic equation is
x² – (4) x + (-21) = 0
(i.e.,) x² – 4x – 21 = 0

Question 2.
A quadratic polynomial has one of its zero 1 + √5 and it satisfies p(1) = 2. Find the quadratic polynomial.
Answer:
Let p(x) = ax² + bx + c be the required quadratic polynomial.
Given p (1) = 2 , we have
a × 1² + b × 1 + c = 2
a + b + c = 2 ——— (1)
Also given 1 + √5 is a zero of p(x)
∴ a(1 + √5)² + b (1 + √5) + c = 0
a( 1 + 5 + 2√5) + b (1 + √5) + c = 0
6a + 2a√5 + b + b√5 + c = 0 ——— (2)
If 1 + √5 is zero then 1 – √5 is also a zero of p (x).
∴ a(1 – √5)² + b (1 – √5) + c = 0
a( 1 – 2√5 + 5) + b (1 – √5) + c = 0
6a – 2a√5 + b – b√5 + c = 0 ——— (3)

Substituting the value of a in equation (4)
5 × – \(\frac{2}{5}\) + 2 × – \(\frac{2}{5}\) × √5 + b√5 = – 2
– 2 – \(\frac{4}{5}\)√5 + b√5 = – 2
b√5 = – 2 + 2 + \(\frac{4}{5}\) . √5
b√5 = \(\frac{4}{5}\) . √5
b = \(\frac{4}{5}\)
Substituting the value of a and b in equation (1), we have

∴ The required quadratic polynomial is
p(x) = \(-\frac{2}{5}\)x² + \(\frac{4}{5}\)x + \(\frac{8}{5}\)
p(x) = \(-\frac{2}{5}\)(x² – 2x – 4)

Question 3.
If α and β are the roots of the quadratic equation x² + √2x + 3 = 0 form a quadratic polynomial with zeros \(\frac{1}{\alpha}, \frac{1}{\beta}\).
Answer:
Given α and β are the roots of the quadratic polynomial
x² + √2x + 3 = 0 ——— (1)

∴ The required quadratic equation whose roots are \(\frac{1}{\alpha}, \frac{1}{\beta}\) is
x² – (sum of the roots)x + product of the roots = 0

Question 4.
If one root of k (x – 1)² = 5x – 7 is double the other root, show that k = 2 or – 25
Answer:
The given quadratic equation is
k(x – 1)² = 5x – 7
k(x² – 2x + 1) – 5x + 7 = 0
kx² – 2kx + k – 5x + 7 = 0
kx² – (2k + 5)x + k + 7 = 0 ———- (1)
Let the roots be α and 2α
Sum of the roots α + 2α = –\(\frac{b}{a}\)

Product of te roots α(2α) = \(\frac{c}{a}\)

Using equation (2) and (3) we have

2(4k² + 20k + 25) = 9k(k + 7)
8k² + 40k + 50 = 9k² + 63k
9k² + 63k – 8k² – 40k – 50 = 0
k² + 23k – 50 = 0
k² + 25k – 2k – 50 = 0
k(k + 25) – 2(k + 25) = 0
(k – 2) (k + 25) = 0
k – 2 = 0 or k + 25 = 0
k = 2 or k = – 25

Question 5.
If the difference of the roots of the equation 2x² – (a + 1)x + a – 1 = 0 is equal to their product then prove that a = 2.
Answer:
The given quadratic equation is
2x² – (a + 1) x + a – 1 = 0 ———– (1)
Let α and β be the roots of the given equation
Given that α – β = αβ —— (2)
Sum of the roots α + β = – \(\frac{b}{a}\)


Substituting the values of α and β in equation (2)

2(a – 1) = a
2a – 2 – a = 0
a – 2 = 0
⇒ a = 2

Question 6.
Find the condition that one of the roots of ax² + bx + c may be
(a) negative of the other
(b) thrice the other
(c) reciprocal of the other.
Answer:
The given quadratic equation is
ax² + bx + c = 0 ——- (1)
Let α and β be the roots of the equation (1) then
Sum of the roots α + β = ——- (2)
Product of the roots αβ = ——- (3)

(a) Given one root is the negative of the other
β = – α
(2) ⇒ α + (-α) = – \(\frac{b}{a}\)
0 = – \(\frac{b}{a}\)
⇒ b = 0
(3) ⇒ α(-α) = \(\frac{c}{a}\)
– α² = \(\frac{c}{a}\)
Hence the required condition is b = 0

(b) Given that one root is thrice the other
β = 3α

When is the required condition?

(c) One root is reciprocal of the other

When is the required condition?

Question 7.
If the equations x² – ax + b = 0 and x² – ex + f = 0 have one root in common and if the second equation has equal roots then prove that ae = 2(b + f).
Answer:
The given quadratic equations are
x² – ax + b = 0 ———- (1)
x² – ex + f = 0 ——— (2)
Let α be the common root of the given quadratic equations (1) and (2)
Let α, β be the roots of x² – ax + b = 0
Sum of the roots α + β = \(-\left(-\frac{a}{1}\right)\)
α + β = a ———- (3)
Product of the roots αβ = \(\frac{b}{1}\)
αβ = b ——– (4)
Given that the second equation has equal roots.
∴ The roots of the second equation are a, a
Sum of the roots α + α = \(-\left(-\frac{e}{1}\right)\)
2α = e ——— (5)
Product of the roots α.α = \(\frac{f}{1}\)
α² = f ———- (6)
ae = (α + β)2α (Multiplying equations (3) and (5))
ae = 2α2 + 2αβ
ae= 2 (f) + 2b From equations (4) and (6)
ae= 2(f + b) Hence proved.

Question 8.
Discuss the nature of roots of
(i) – x² + 3x + 1 = 0
(ii) 4x² – x – 2 = 0
(iii) 9x² + 5x = 0.
Answer:
(i) -x² + 3x + 1 = 0
⇒ comparing with ax² + bx + c = 0
∆ = b² – 4ac = (3)² – 4(1)(-1) = 9 + 4 = 13 > 0
⇒ The roots are real and distinct

(ii) 4x² – x – 2 = 0
a = 4, b = -1, c = -2
∆ = b² – 4ac = (-1)² – 4(4)(-2) = 1 + 32 = 33 >0
⇒ The roots are real and distinct

(iii) 9x² + 5x = 0
a = 9, b = 5, c = 0
∆ = b² – 4ac = 5² – 4(9)(0) = 25 > 0
⇒ The roots are real and distinct

Question 9.
Without sketching the graphs, find whether the graphs of the following functions will intersect the x-axis and if so in how many points.
(i) y = x² + x + 2
(ii) y = x² – 3x – 7
(iii) y = x² + 6x + 9
Answer:
(i) y = x² + x + 2
y = x² + x + 2 ——— (1)
Compare this equation with the equation
ax² + bx + c = 0
we have a = 1 , b = 1, c = 2
b² – 4ac = 1² – 4 × 1 × 2 = 1 – 8
b² – 4ac = – 7 < 0
Since the discriminant is negative the quadratic equation has no real roots and therfore the graph does not meet x-axis.

(ii) y = x² – 3x – 7
y = x² – 3x – 7 ——— (2)
Compare this equation with the equation ax² + bx + c = 0
we have a = 1 , b = – 3 , c = – 1
b² – 4ac = (-3)² – 4(1)(-1)
= 9 + 4
b² – 4ac = 13 > 0
Since the discriminant is positive the quadratic equation has real and distinct roots and therefore the graph intersect the x – axis at two different points,

(iii) y = x² + 6x + 9
y = x² + 6x + 9 ——— (3)
Compare this equation with the equation
ax² + bx + c = 0
we have a = 1 , b = 6, c = 9
b² – 4ac = 6² – 4 × 1 × 9
= 36 – 36 =0
Since the discriminant is zero the quadratic equation has real and equal roots and therefore the graph touches the x-axis at one point.

Question 10.
Write f(x) = x² + 5x + 4 in completed square form.
Answer:
The given quadratic equation is
f(x) = x² + 5x + 4
Let y = x² + 5x + 4
y – 4 = x² + 5x

Tamilnadu State Board New Syllabus Samacheer Kalvi 5th English Guide Pdf Term 3 Poem 3 Social Responsibility Text Book Back Questions and Answers, Summary, Notes.

Tamilnadu Samacheer Kalvi 5th English Solutions Term 3 Poem 3 Social Responsibility

5th English Guide Social Responsibility Text Book Back Questions and Answers

A. Answer the following questions:

Question 1.
When does the world become green?
Answer:
The world becomes green when we keep our surroundings clean.

Question 2.
Who is responsible for society?
Answer:
Everyone is responsible for society.

Question 3.
When do you feel proud?
Answer:
I feel proud when I keep the surroundings clean, putting the litter in a trash can.

Question 4.
What should we vow for?
Answer:
We should vow to do social welfare.

Question 5.
Are you the first to protect nature?
Answer:
Yes.

B. Pick out the rhyming words and write:

Question 1.

1.green
2.human
3.will
4.welfare

Answer:

1.green	a. clean
2.human	b. can
3.will	c. ill
4.welfare	d. care

Let Us Know:

Past Perfect Tense (கடந்தகால வினைமுற்று):

The past perfect tense is used to show that something happened before another action in the past.
கடந்த காலத்தில் ஒரு செயலுக்கு முன்பே இன்னொரு செயல் நடந்து முடிந்து விட்டதை குறிப்பது கடந்தகால வினைமுற்று ஆகும். It can also be used to show that something happened before a specific time in the past.

We know the forms of the verbs, they are:

The past participle form is used in past perfect tense with auxiliary had.

A. Fill in the blanks:

Example:
I had given him the book.

Question 1.
We ______ to the park. (go)
Answer:
We had gone to the park.

Question 2.
You ______ to your uncle’s house. (be)
Answer:
You had been to your uncle’s house.

Question 3.
He ______ before 5 ‘o’ clock. (sleep).
Answer:
He had slept before 5 ‘o’clock.

Question 4.
She ______ the bill. (pay)
Answer:
She had paid the bill.

Question 5.
They ______ him before the party. (meet)
Answer:
They had met him before the party.

Question 6.
It ______ before I touch it. (break)
Answer:
It had broken before I touched it.

Let us see when to use past perfect tense:
Event happened before another in the past:

B. Complete the following sentences using past perfect tense:

Question 1.
The bus _____ the bus stop before I went. (leave)
Answer:
The bus had left the bus stop before I went.

Question 2.
The exam _____ when I reached the exam hall. (start)
Answer:
The exam had started when I reached the exam hall.

Question 3.
She _____ the apple as I told her to stop. (eat)
Answer:
She had eaten the apple as I told her to stop.

Question 4.
The satellite ______ on the moon before they gave the command. (land)
Answer:
The satellite had landed on the moon before they gave the command.

Question 5.
Raju ______ to the ground before others arrived. (arrive)
Answer:
Raju had arrived to the ground before others arrived. (arrive)

Future Perfect Tense (எதிர்கால வினைமுற்று):

Future perfect tense is used for actions that will be completed before some other point in the future.
எதிர்காலத்தில் ஒரு செயலை முடிப்பதற்கு முன்னால், இன்னொரு செயலை செய்து முடிக்கப்போவதை குறிப்பது எதிர்கால வினைமுற்று ஆகும்.

The past participle form is used in future perfect tense with auxiliary will have. Come let us use it:

A. Fill in the blanks using future perfect tense:

Example :
I will have reached the place by 6 pm.

Question 1.
We ______ the painting by tomorrow. (complete)
Answer:
We will have completed the painting by tomorrow.

Question 2.
You ______ the match by this time tomorrow. (win)
Answer:
You will have won the match by this time tomorrow.

Question 3.
They ______ everyone to the marriage by next week. (invite)
Answer:
They will have invited everyone to the marriage by next week.

Question 4.
He ______ all the money within an hour. (spend)
Answer:
He will have spent all the money within an hour.

Question 5.
She ______ job in America by next year. (get)
Answer:
She will have got job in America by next year.

Question 6.
It ______ all the candies. (eat)
Answer:
It will have eaten all the candies.

B. Mark (✓) if it is past perfect tense or (x) Future perfect tense:

Question 1.
I had gone to my grandma’s home.
Answer:
(✓) Past perfect

Question 2.
The boy will have grown up like a man in a few years.
Answer:
(X) Future perfect

Question 3.
She will have made the cake by 8 ‘o’clock.
Answer:
(X) Future perfect

Question 4.
They had cooked the vegetables.
Answer:
(✓) Past perfect

Question 5.
Muthu will have returned from Srilanka by next month.
Answer:
(X) Future perfect.

C. Change the sentence into past perfect tense and future perfect tense:

Question 1.
I have posted the letter.
Answer:
Past perfect: I had posted the letter.
Future perfect: I will have posted the letter.

Question 2.
She has bought a violin.
Answer:
Past perfect: She had bought a violin.
Future perfect: She will have bought a violin.

Question 3.
Akash has jumped into the well.
Answer:
Past perfect: Akash had jumped into the well.
Future perfect: Akash will have jumped into the well.

Question 4.
We have built a house in our village.
Answer:
Past perfect: We had built a house in our village.
Future perfect: we will have built a house in our village.

Question 5.
They have cooked their meal.
Answer:
Past perfect: They had cooked the meal.
Future perfect: They will have cooked the meal.

D. Fill the sentences with the appropriate Auxilliary:
(had), (will have)

Question 1.
Maha ______ asked a question to his father.
Answer:
Maha had asked a question to his father.

Question 2.
She ______ attended the meeting by tomorrow.
Answer:
She will have attended the meeting by tomorrow.

Question 3.
The fly ______ sat in the food before she covered it.
Answer:
The fly had sat in the food before she covered it.

Question 4.
Niru ______ joined her family in 2 years.
Answer:
Niru will have joined her family in 2 years.

Question 5.
The book ______ won him the award.
Answer:
The book had won him the award.

Let us listen:

Listen to the audio and tick (✓) if the statements are true:

Question 1.
Chennai is the fourth largest city in India to receive more rain.
Answer:
True

Question 2.
The airport is not closed.
Answer:
False

Question 3.
People were not able to get their food.
Answer:
True

Question 4.
The power supply in many areas is normal.
Answer:
False

Question 5.
It rained because of a depression in Bay of Bengal.
Answer:
True

Let us speak:

Storry Telling:

The following steps are involved in Story-telling:
Step 1: Choose the story you want to tell.
Step 2: Tell the place where the story is happening.
Step 3: Tell who the characters are.
Step 4: Tell three events that lead to the end of the story.
Step 5: End the story.

Example:
The Ant and the Grasshopper:

In a deep forest near the mountains, lived an ant and a grasshopper. The ant worked hard in the summer and saved food for the winter. The grasshopper played in the Sun without collecting food. The grasshopper always called the ant to play, but the ant wanted to save food for winter. It was now winter, the ant had food to eat but the grasshopper did not. We should work hard and save.

Try to tell your friend a story on your own.

5th English Guide Social Responsibility Additional Questions and Answers

I. Answer the following:

Question 1.
List any four social responsibility given in the poem.
Answer:

1. Keep your surroundings clean.
2. Save electricity and do not waste.
3. Put the litter in the trash can.
4. Take care of nature.

II. Story telling:

Title: Wise King Solomon

King Solomon was known for his wisdom. Queen Sheeba wanted to test his wisdom. She took two identical flower garlands to Solomon. One was real and the other a paper garland. She asked the king to identify the real one. Solomon asked to open the windows. Soon a swarm of bees settled on the real garland. Solomon handed the real garland to Sheeba and she was happy.

Social responsibility Summary in English and Tamil

Our world becomes green,
When you keep the surroundings clean.
All of us are responsible for our society,
To take care of it is our duty.
Be proud of yourself as a human,
When you put the litter in a trash can.
Reduce the use of electricity by will,
And help the Earth grow without any
All should vow to do social welfare,
I will start with nature’s care.

நம் உலகம் பச்சை பசேல் என மாறுகிறது,
சுற்றுப்புறத்தை நீங்கள் சுத்தமாக வைத்திருக்கும்
போது நமது சமுதாயத்திற்கு நாம் அனைவரும் பொறுப்பானவர்கள்
அதை கவனித்துக் கொள்வது நமது கடமை.
ஒரு மனிதர் என்பதற்காக உங்களைப் பற்றி பெருமிதம் கொள்ளுங்கள்,
நீங்கள் குப்பையை அதற்கான குப்பைத்தொட்டியில் போடும் போது.
மின்சார பயன்பாட்டை ஓர் உறுதியுடன்,
குறையுங்கள் எந்த பாதிப்பும் இல்லாமல் இந்த பூமி வளர.
உதவுங்கள் சமூக நலனுக்கு ஏதேனும் செய்ய அனைவரும் உறுதிமொழி எடுப்போம்,
இயற்கையை பாதுகாத்து பராமரிப்பதுடன் நான் தொடங்குவேன்.

Social responsibility Glossary:

Litter – Waste (குப்பை)
Proud – Glad (பெருமிதம், மகிழ்ச்சி)
Reduce – Make something less (குறைத்தல்)
Responsible – In charge of (பொறுப்பு)
Society – Community (சமுதாயம்)
Trash can – Dust bin (குப்பைத் தொட்டி)
Vow – Pledge, promise (உறுதி மொழி)
Welfare – Comfort and security (பொதுநலன்)
Will – Determination (உறுதி)

Tamilnadu State Board New Syllabus Samacheer Kalvi 7th Social Science Guide Pdf Geography Term 3 Chapter 3 Road Safety Text Book Back Questions and Answers, Notes.

Tamilnadu Samacheer Kalvi 7th Social Science Solutions Geography Term 3 Chapter 3 Road Safety

7th Social Science Guide Road Safety Text Book Back Questions and Answers

I. Choose the Correct answer:

Question 1.
Road safety is meant for
a) Passersby
b) drivers
c) public
d) all who use roads
Answer:
d) all who use roads

Question 2.
Road accidents affect a country’s
a) improvement
b) life
c) finance
d) all the above
Answer:
d) all the above

Question 3.
Permit refers to
a) permission for driving
b) permission for carrying goods
c) certificate for drivers
d) registration of vehicles
Answer:
a) permission for driving

Question 4.
Raksha safe drive is a device useful for
a) pedestrians
b) motorists
c) car drivers
d) passengers
Answer:
c) car drivers

Question 5.
Road safety week celebration was first imitated in India in the year
a) 1947
b) 1989
c) 1990
d) 2019
Answer:
b) 1989

II. Fill in the blanks:

1. The most useful invention of man for transport is ………………….
Answer:
wheel

2. Using …………………. is inevitable in our journey of life.
Answer:
Helmet

3. Too many vehicles on the road cause …………………. and …………………. pollution.
Answer:
Air, Noise

4. …………………. is the monetary supporter of a family.
Answer:
Breadwinner

5. In case of emergency for medical assistance call …………………. for help.
Answer:
108

III. Match the following:

A	B
1. Informatory sign	a) Traffic lights
2. The Legal Metrology Act	b) Narrow bend sign
3. Mandatory sign	c) Petrol pump sign
4. Cautionary sign	d) License
5. Right to drive a vehicle	e) walkers

Answer:

A	B
1. Informatory sign	c) Petrol pump sign
2. The Legal Metrology Act	e) walkers
3. Mandatory sign	a) Traffic lights
4. Cautionary sign	b) Narrow bend sign
5. Right to drive a vehicle	d) License

IV. Consider the following statements:

Question 1.
Tick the appropriate answer:
Assertion (A) : Car pooling is the use of vehicles by turns. Reason (R) : It saves fuel, time and money and also.
a) A is correct and R is not correct
b) A is correct and R is also correct
c) A is wrong and R is correct
d) Both are wrong
Answer:
c) A is wrong and R is correct

Question 2.
Find the odd one
a) car
b) trucks
c) tempos
d) aeroplanes
Answer:
d) aeroplanes

Question 3.
Consider the following statements and choose the correct answer from the codes given below.

a) Road safety education in the school curriculum is an additional burden for the students.
Answer:
False

b) An ounce of practice is worth more than tons of preaching.
Answer:
True

c) Hoarding on roads has to be banned.
Answer:
True

d) Following road safety rules from childhood will become a habit in future.
Answer:
True

V. Answer in one or two sentences:

Question 1.
What are the distractors while driving?
Answer:

• This is a larger threat and the leading cause of road accidents.
• It is the distraction of the driver, engaging in any other activity while driving.
• It may be talking over the mobile phone or texting messages or engaging in any activities with attention diverted from driving.

Question 2.
Mention the 2 safety gears for safe driving.
Answer:

• Obey the traffic rules and signs.
• Keep vehicle fit.

Question 3.
Why is not safe to drive at night?
Answer:

• Extra alertness is needed while driving at night.
• Uncontrolled sleep, tiredness due to the long drive, poor lighting on the road can cause fatal accidents.

Question 4.
When can a person obtain the night to drive a vehicle?
Answer:
As per Indian law, one should be eligible to get a driving license at the age of 18.

Question 5.
How can media promote road safety among the public?
Answer:
Mass media and journals could play a key role to raise awareness of road safety. In particular, they can disseminate preventive messages and promote safe behaviours, increase people’s knowledge and understanding of the gravity of the problem, and advocate for safer roads and systems.

VI. Answer the following in detail:

Question 1.
List out the documents necessary for an Indian while driving.
Answer:
One who drives a vehicle should have undergone the training and tests to obtain a driving license.
It is compulsory to have the following documents:

• driving license
• registration certificate of the vehicle
• Insurance certificate
• Taxation certificate
• fitness certificate and permit.

Question 2.
What is the need for including road safety education in the school curriculum?
Answer:

• Provide Road Safety education since childhood.
• It has to be made a part of the school curriculum, syllabus, textbook and included in competition on road safety.
• Activities like writing slogans, essays, and paintings on this theme should be conducted for reinforcement.

Question 3.
How can parents teach their children road safety rules?
Answer:

• Parents and Teachers play a vital role in imparting road safety Education to young ones.
• If a child’s parent violates the traffic rules, the child too will initiate the same in the future.
• So the elders have to set an example for them in adhering to the safety rules and regulations.
• Video and computer games that simulate driving should be banned by the government.
• Help your children learn about traffic signals and rules.
• Warn them not to run across or along the road.
• Teach them to use the footpath while walking on the road.

HOTs:

Question 1.
Knowing the road safety rules, how will you influence your parents and relatives?
Answer:

1. We will educate parents on following road safety rules.
2. Explain the risk of not wearing a helmet.
3. We will insist our parents wear a seat belt while driving a car.
4. We will tell them not to exceed the speed limit while riding or driving.

Question 2.
If the wheel had not been invented, what might have been our mode of transport?
Answer:

• If the wheel had not been invented, there is a need for road transport.
• Walking would have been the only mode of transport.

7th Social Science Guide Road Safety Additional Important Questions and Answers

I. Choose the Correct answer.

Question 1
……………….. is the world’s largest contributor to road accidents.
a) China
b) India
c) Africa
d) none
Answer:
b) India

Question 2.
India accounts for about ……………….. of road accident fatalities at worldwide.
a) 50%
b) 70%
c) 10%
d) 20%
Answer:
c) 10%

Question 3.
……………….. failure can result in crucial collisions.
a) Brake
b) Accelerator
c) Gear
d) all of these
Answer:
a) Brake

Question 4.
The Government of India observes; Road Safety Week; awareness during ……………….. Every year.
a) December
b) January
c) November
d) none
Answer:
b) January

Question 5.
Every country celebrates ……………….. week.
a) Road safety
b) Road rules
c) Regulation
d) Traffic Signs
Answer:
a) Road safety

II. Fill in the blanks:

1. Accident occurs to the ……………….. of the driver, engaging in any other activity while driving.
Answer:
distraction

2. ……………….. is a major traffic violation of rules.
Answer:
Reckless driving

3. Increase of ……………….. on the road create a heavy traffic jam and cause more pollution.
Answer:
vehicles
4. Impatience of ……………….. and violation of traffic rules result in accidents.
Answer:
Pedestrians

5. Avoiding the use of ……………….. for two-wheelers lead to unwanted happenings.
Answer:
helmets

6. ……………….. is a device capable of automatic crash detection.
Answer:
Raksha safe drive

7. ……………….. will reduce the number of vehicles on the road.
Answer:
Carpooling

8. Parents and Teachers play a vital role in imparting road safety Education ………………..
Answer:
young ones

9. ……………….. is a healthy habit and reduces pollution.
Answer:
Cycling

10. ……………….. act as silent conductors of the traffic on the road.
Answer:
Traffic signs

III. Match the following

A	B
1. Night driving	a) Safe instrument
2. Driving license	b) Loss their Stability
3. Raksha drive	c) Road safety week
4. Drinking alcohol	d) tiredness
5. January month	e) Age 18

Answer:

A	B
1. Night driving	d) tiredness
2. Driving license	e) Age 18
3. Raksha drive	a) Safe instrument
4. Drinking alcohol	b) Loss their Stability
5. January month	c) Road safety week

IV. Consider the following statements:

Question 1.
Assertion (A) : Reckless driving is a major traffic violation of rules.
Reason (R) : In which the driver Purposely disregards the rules of the road.
a) A is correct and R is not correct
b) A is correct and R is also correct
c) A is wrong and R is correct
d) Both are wrong
Answer:
b) A is correct and R is also correct

Question 2.
Find the odd one.
a) STOP OR SLOW DOWN
b) BUCKLE UP
c) WEAR HELMET
d) KEEP VEHICLES FIT
e) PROHIBITION the hoarding soil
Answer:
e) PROHIBITION the hoarding soil

V. Answer in one or two sentences :

Question 1.
Define Raksha safe drive.
Answer:
Raksha safe drive is a device capable of automatic crash detection, two-way call connectivity, GPS tracking, engine health monitoring, and a smart panic button.

Question 2.
Write short notes on Carpooling.
Answer:
Carpooling is the sharing of car journeys so that more than one person travels in the car, and prevents the need for more cars to the same location.

Question 3.
Write the impact of Alcohol.
Answer:

• Alcohol leads to fatal accidents.
• Alcohol affects your vision, judgment, and ability to react quickly.

VI. Answer the following in detail:

Question 1.
Explain the Golden Rules for Road Safety.
Answer:

• Stop or slow down
• Buckle up
• Obey traffic rules and signs
• Obey speed limits
• Keep vehicle fit
• Never use mobile while driving
• Wear helmet
• Never drive dangerously
• Be courteous
• Never mix drinking and driving.

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

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

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

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.

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.

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.

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:

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.

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:

Purpose:
To measure density (or) relative density of the liquid.

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.

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

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

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, ρ_Hg = 13.6 × 10³ kg/cm³
Acceleration due to gravity, g = 9.8 m/s²

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.

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. 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.

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.

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]

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.

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.

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.

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.

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.

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]

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

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

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

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

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

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

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

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

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

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

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

(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.

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.

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.

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.

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).

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.

Question 2.
How will you calculate fluid pressure?
Answer:

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.

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.

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’.

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.

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.

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.

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.

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 …………….?

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

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

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

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

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 :

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.

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.

Tamilnadu State Board New Syllabus Samacheer Kalvi 4th English Guide Pdf Term 2 Supplementary Chapter 2 Save Wisely Text Book Back Questions and Answers, Summary, Notes.

Tamilnadu Samacheer Kalvi 4th English Solutions Term 2 Supplementary Chapter 2 Save Wisely

4th English Guide Save Wisely Text Book Back Questions and Answers

A. Fill in the blanks.

Question 1.
Every year the children visit their _____________.
Answer:
Grandparents

Question 2.
At the end of the festival , Kamali and Senthil saved ___________.
Answer:
Some amount

Question 3.
Savings is done after fulfilling the ____________
Answer:
Basic needs

Question 4.
Senthil bought a ___________ from his savings.
Answer:
Camera

Question 5.
Kamali gave her savings to _____________.
Answer:
Her father

B. Answer the following questions.

Question 1.
What did the children buy with money they have?
Answer:
The children bought sweets, toys, chocolates or packed food items.

Question 2.
What did the grandfather announce?
Answer:
He announced that the children should save the money they get over the course of a year and spend it purposefully.

Question 3.
What happened to Jayan?
Answer:
Jayan got sick due to food poisoning.

Question 4.
What did Kamali get as gift?
Answer:
Kamali got a brand new fulte as gift.

Question 5.
What will you do with your savings?
Answer:
I will buy a gift for my mother and father.

Answer the following Additional Questions and Answers.

Question 1.
Why did the children visit their native village?
Answer:
They visited their native village for the car festival that lasted for three days.

Question 2.
What did the family members and relatives would give their children?
Answer:
They would give them money to buy sweets and toys.

Question 3.
What would the children do with that money?
Answer:
They would spend all the money and never saved the money at all.

Question 4.
Were the children excited by the announcement?
Answer:
No, the children were not excited by the announcement.

Question 5.
What did Jayan and Kauvery decide to do?
Answer:
Jayan and Kauvery decided to enjoy the festival to the fullest. They bought every single type of food available across the shops.

Question 6.
Who were the eldest of the kids?
Answer:
The eldest of the kids were Kamali and Senthil.

Question 7.
How did Senthil and Kamali save every rupee they got?
Answer:
They controlled their desires and saved every rupee they got.

Question 8.
How much did they manage to save by the end of the festival?
Answer:
They managed to save around three hundred rupees by the end of the festival.

Question 9.
What did Senthil do?
Answer:
He opened savings account in the nearest post office.

Question 10.
What was Senthil’s dream?
Answer:
Senthil’s dream was to buy a camera.

Let us read aloud

Read the passage three times on your own. Colour a Piggy bank each time you read.

Piggy bank is a coin box used by children. The real use of a piggy bank is to store coins. Piggy banks look like pigs. They come in many shapes and sizes. In Tamil, they are known as Hundial. It is a red, mud pot. We can drop the coins into the pot. Once the pot is full, we must break the pot and use they coins. Start saving with your hundial today!

Question 1.

Hundial is a ____________ pot.
Answer:
Red, mud

Question 2.

Mostly piggy banks looks like ___________
Answer:
Pigs.

Question 3.
The main idea of the passage is ___________
(a) To buy a piggy bank.
(b) To save.
Answer:
(b) To save

Let us write

This month you have managed to save Rs. 100 from your pocket money. Fill out the challan to deposit it in your Savings Account at the post office.

Question 1.

Answer:

Fill up the withdrawal form to withdraw Rs.200 from your Savings Account.

Question 1.

Answer:

I can do

A. Fill in the blanks.

Question 1.
Moles dig __________ to catch worms.
Answer:
Long and wide tunnel

Question 2.
Leaf cutter ants drink ___________
Answer:
Leaf sap

Question 3.
Kamali gave her savings to ____________.
Answer:
Her father

B. Join the word with the correct prefix.

Question 1.

Answer:

1. Prepaid
2. Resend
3. Unable
4. Discontinue

C. Match the rhyming words.

Question 1.
Save ___________
Answer:
Gave

Question 2.
Countries __________
Answer:
Pantries

Question 3.
larder ___________
Answer:
Starter

D. Recite the poem with correct intonation.
Answer:
Activity to be done by the students

E. Write the words given in the bracket in correct tenses.

Question 1.
I __________ (see) him accidently.
Answer:
Saw

Question 2.
We ____________ (move) back to city yesterday.
Answer:
Answer:
Moved

Question 3.
Rani ____________ (meet) Rita tomorrow.
Answer:
Wil meet

F. Write the past form of the verbs.

Question 1.

run ____________
Answer:
Ran

Question 2.

eat ____________
Answer:
Ate

Question 3.

swim ____________
Answer:
Swam

Save Wisely Summary in English and Tamil

Every year, Kamali and her cousins would visit their grandparents in their native village for the car festival that lasted for three days. The entire village will be in a festive mood. The children were the most excited. The family members and relatives would give the children money to buy sweets and toys.

ஒவ்வொரு வருடமும் கமலியும், அவனுடைய ஒன்றுவிட்ட உறவுகளும் (சகோதர/ சகோதரிகள்) தங்கள் பூர்வீக கிராமத்தில் உள்ள தாத்தா, பாட்டியை காணவும் அங்கு மூன்று நாட்கள் நடைபெறும் தேர்த்திருவிழாவை காணவும் செல்வர். மொத்த கிராமமுமே பண்டிகைக்கால கொண்டாட்டத்தில் இருக்கும். குழந்தைகள் தான் இதில் மிக உற்சாகமாக இருப்பர். குடும்பத்தாரும், உறவினரும் தங்கள் குழந்தைகளுக்கு இனிப்புகளும், பொம்மைகளும்
வாங்க பணம் தருவர்.

The children would buy toys, chocolates, sweets or packed food items. They would spend all the money, and never saved the money at all. Their grandfather felt that the children should learn to save and use their money wisely. So, this year, he announced that the children should save the money they get over the course of a year, and spend it purposefully.

பொம்மைகள், சாக்லேட்கள், இனிப்புகள் அல்லது பாக்கெட்டுகளில் அடைக்கப்பட்ட உணவுகளை, குழந்தைகள் வாங்குவர். அவர்கள் பணத்தை சேமிக்காமல் அனைத்தையும் செலவு செய்வர். அவர்களுஅவர்களுடைய பாட்டனார், குழந்தைகள் சேமிக்க கற்க வேண்டுமெனவும் பணத்தை விவேகமாக செலவு செய்ய அறிய வேண்டுமெனவும் நினைத்தார். அதனால், இந்த வருடம் முழுவதும் அவர்கள் சேமிக்கும் பணத்தை உபயோகமாக செலவழிக்க வேண்டுமென அறிவித்தார்.

The children werenot at all excited by the announcement. Rajan and Mala were the youngest of the kids.They did not take the grandfather seriously. They spent their money on sweets and toys. The other siblings, Jayan and Kavery, decided to enjoy the festival to the fullest.

இந்த அறிவிப்பால் குழந்தைகள் மகிழவில்லை ராஜனும், மாலாவும் தான் இருப்பதிலேயே இளையவர்கள். அவர்கள் தாத்தா கூறியதை பெரிதாக எடுத்துக் கொள்ளவில்லை . அவர்கள் தங்கள் பணத்தை இனிப்புகள் மற்றும் பொம்மைகள் வாங்குவதில் செலவிட்டனர். அவர்களின் உடன்பிறப்புகள் ஜெயனும், காவேரியும் கூட அந்த திருவிழாவை முழுமையாய், சந்தோஷமாய் அனுபவிக்க முடிவெடுத்தனர்.

They bought every single type of food available across the shops. On the second day, Jayan got sick due to poisoning. So he decided to spend food the money only on toys. The eldest of the kids were Kamali and Senthil. They were determined to save the money and use it purposefully. So they controlled their desires and saved every rupee they got.

எந்தவிதமான உணவு கடைகளில் கிடைத்தாலும் அதை வாங்கினர். மறு நாள் ஜெயன் உண்ட உணவு நஞ்சேற்றம் கண்டதால், அவன் பணத்தைக் கொண்டு பொம்மைகள் வாங்க சிட்டமிட்டான். அந்த கமந்கைகளிலேயே கமலியம். செந்திலும் தான் பெரியவர்கள். அவர்கள் தங்கள் ஆசைகளை அடக்கிக் கொண்டு, கிடைத்த ஒவ்வொரு ரூபாயையும் சேமித்தனர்.

By the end of the festival, they managed to save around three hundred rupees. Grandfather was so happy to see their effort.

திருவிழா முடிவடையும் நேரத்தில், அவர்களால் முந்நூறு ரூபாய் சேமிக்க முடிந்தது. அவர்கள் முயற்சியில் பாட்டனார் ஆனந்தமடைந்தார்.

Senthil, when he went home, took his father to the nearest post office and opened a savinas account. He saved all his pocket money and found new ways to save money like he started to walk instead of taking the bus. He kept his stationeries safely so that he did not have to keep buying them. He re-used his old books to save money.

செந்தில் வீடு திரும்பியதும் தன் தந்தையை அழைத்துக் கொண்டு அருகிலுள்ள தபால் ஆபீசுக்கு சென்று, ஒரு சேமிப்புகணக்கு துவங்கினான். தன் கைச்
செலவுக்கு தரப்படும் பணத்தை சேமித்து வைத்தவுடன், பணம் சேமிக்க புதுப்புது வழிகளை கண்டுபிடித்தான். அவன் பேருந்தில் செல்வதற்கு பதில் நடந்து செல்ல ஆரம்பித்தான். தன் எழுது பொருட்களை பத்திரமாக ne வைத்திருந்து, மேலும் வாங்குவதை தவிர்த்தான். தன் பழைய புத்தகங்களை மறுபடி உபயோகித்து பணத்தை சேமித்தான்.

Soon, his father made him understand that savings is done after using the money for basic needs. So Senthil bought new books to take notes in his class. Senthil’s dream was to buy a camera. At the end of the year, his father checked his savings and bought him the latest camera with
his savings!

ஆனால், அவன் தந்தையார் அவனிடம் அடிப்படை தேவைகளுக்கு பயன்படுத்திய பிறகுதான், பணத்தை சேமிக்க வேண்டுமென உணர வைத்தார். அதனால் செந்தில் புதிய புத்தகங்களை வாங்கி வகுப்பில் குறிப்பெடுத்தான் செந்திலுக்கு வருட இறுதியில் ஒரு காமெரா வாங்க எண்ண ம் இருந்தது. வருட இறுதியில் அவன் சேமிப்பை சோதித்த அவனுடைய தந்தையார் அவனுக்கு, அவனுடைய சேமிப்பில் இருந்தே ஒரு சமீபத்திய காலத்திற்குரிய காமெரா வாங்கித் தந்தார்.

Kamali had a clear plan. She had a friend named Anandhi. Anandhi’s father was a futist. They lived in the same street, so the girls used to visit each other often. On many of these occasions, Anandhi used to teach her to play the flute. Kamali always wanted to buy a fute.

கமலிக்கு ஒரு தெளிவான திட்டம் இருந்தது. அவள் தோழியின் பெயர் ஆனந்தி என்பதாகும். ஆனந்தியின் அப்பா ஒரு புல்லாங்குழல் கலைஞர். அவர்கள் இருவரும் ஒரே தெருவில் வசித்ததால், ஒருவரை ஒருவர் அடிக்கடி சந்தித்துக் கொள்வர். பல சமயங்களில்’ கமலிக்கு, ஆனந்தி புல்லாங்குழல் வாசிக்க கற்றுத் தருவாள். கமலி எப்போதும் ஒரு புல்லாங்குழல் வாங்கவேண்டுமென்ற எண்ண த்தோடு இருந்தாள்.

At the end of one year, she managed to save some amount. At that time,her father needed money urgently asked if he could use her savings. He promised to return the money soon. Kamali gave her savings to her father. Although she was proud of helping her father, she still wanted to buy the flute. She was disappointed.

ஒரு வருட முடிவில் அவளால் சிறிது பணம் சேமிக்க முடிந்தது. அந்த நேரத்தில் அவள் தந்தைக்கு அவசரமாக and பணம் தேவைப்பட்டதால், அவளுடைய பணத்தை உபயோகப்படுத்திக் கொள்ளலாமா என்று கேட்டார். அந்த பணத்தை விரைவில் திருப்பி தந்து விடுவதாகவும்கூறினார். தன் தந்தைக்கு உதவியதற்காக அவள் மகிழ்ந்தாலும் அவளுக்கு புல்லாங்குழல் வாங்குவது எண்ணமாக இருந்ததால் அவள் ஏமாற்றமடைந்தாள்.

Soon it was time to visit the village. Everyone was happy to meet each other after one year. On the day of the car festival, the whole family gathered in the village. Everyone in the family shared about the year gone one by one. After dinner, Senthil brought his new camera and told grandpa how he had saved and bought the camera. Grandpa was very proud and happy. He congratulated him.

கிராமத்துக்கு செல்லும் நேரமும் வந்துவிட்டது. ஒரு வருடத்திற்கு பின்னர் ஒருவரை ஒருவர் சந்தித்து ஆனந்தம் அடைந்தனர். திருவிழா அன்று மொத்த குடும்பமும் கிராமத்தில் குழுமி இருந்தது. குடும்பத்தில் இருந்தஒவ்வொருவரும் கடந்த வருடத்தை பற்றி, ஒவ்வொருவராக அனுபவங்களை பகிர்ந்து கொண்டனர். உணவிற்கு பிறகு,செந்தில் தாத்தாவிடம், தான் வாங்கிய புது காமெராவை காட்டினான். தாத்தா பெருமையும், மகிழ்ச்சியும் பொங்க அவனை பாராட்டினார்.

Meanwhile, Kamali’s father gave grandpa a gift and said something in his ears. Grandpa smiled and called Kamali. He gave her the aift. Her savings were used to buy the gift. Kamali eagerly opened the box and found a brand new flute. Her eyes were moist with tears. The whole family asked her to play the flute.

இதனிடையே கமலியின் தந்தையார், தாத்தாவின் காதுகளில் ரகசியமாக எதையோ கூறி ஒரு பரிசை அளித்தார். தாத்தா புன்னகையுடன் கமலியை அழைத்து அந்த பரிசை கொடுத்தார். அவளுடைய. சேமிப்பை கொண்டு அந்த பரிசை வாங்கியதாக, தெரிவிக்கப்பட்டது. கமலி ஆவலுடன் அந்த பெட்டியை திறந்து பார்த்ததும் அதில் ஒரு புத்தம் புதிய புல்லாங்குழல் இருந்தது. அவள் கண்கள் அதைக் கண்டதும் கண்ணீரால் ஈரமானது. மொத்த குடும்பமும் அவளை புல்லாங்குழல் வாசிக்கக் கேட்டுக் கொண்ட னர்.

Kamali played a song that her friend had taught her. Senthil started clicking pictures of the event with his camera.

தன் தோழி கற்றுக் கொடுத்த ஒரு பாடலை, கமலி வாசித்துக் காட்டினாள். செந்தில் காமெராவில் அதை படங்களாக எடுத்தான்.