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Tamilnadu Samacheer Kalvi 10th Science Solutions Chapter 22 Environmental Management

Samacheer Kalvi 10th Science Environmental Management Text Book Back Questions and Answers

I. Fill in the blanks:

  1. Deforestation leads to ……… in rainfall.
  2. Removal of soil particles from the land is called ……….
  3. Chipko movement is initiated against ……….
  4. ……….. is a biosphere reserve in Tamilnadu.
  5. Tidal energy is ………. type of energy.
  6. Coal, petroleum and natural gas are called ……… fuels.
  7. ……….. is the most commonly used fuel for the production of electricity.

Answer:

  1. Decrease
  2. Soil Erosion
  3. Deforestation
  4. Nilgiris
  5. Non-conventional
  6. Fossil
  7. Coal

Samacheer Kalvi 10th Science Guide Chapter 22 Environmental Management

II. State whether True or False. Correct the statements which are false:

  1. Biogas is a fossil fuel.
  2. Planting trees increases the groundwater level.
  3. Habitat destruction cause loss of wile life.
  4. Nuclear energy is a renewable energy
  5. Overgrazing prevents soil erosion.
  6. Poaching of wild animals is a legal act.
  7. National park is a protected park.
  8. Wild life protection act was established in 1972.

Answer:

  1. False – Biogas is a natural gas
  2. True
  3. True
  4. False – Nuclear energy is non-renewable energy
  5. False – Overgrazing causes soil erosion
  6. False – Poaching of wild animals is an illegal act.
  7. True
  8. Tme

III. Match the following:

Samacheer Kalvi 10th Science Guide Chapter 22 Environmental Management 1
Answer:
A. (iii)
B. (v)
C. (vi)
D. (ii)
E. (i)
F. (iv)
G. (vii)

IV. Choose the correct answer:

Question 1.
Which of the following is / are a fossil fuel?
(i) Tar, (ii) Coal, (iii) Petroleum
(a) (i) only
(b) (i) and (ii)
(c) (ii) and (iii)
(d) (i), (ii) and (iii)
Answer:
(c) (ii) and (iii)

Question 2.
What are the steps will you adopt for better waste management?
(a) reduce the amount of waste formed
(b) reuse the waste
(c) recycle the waste
(d) all of the above
Answer:
(d) all of the above

Question 3.
The gas released from vehicles exhaust are:
(i) carbon monoxide
(ii) Sulphur dioxide
(iii) Oxides of nitrogen:
(a) (i) and (ii)
(b) (i) and (iii)
(c) (ii) and (iii)
(d) (i), (ii) and (iii)
Answer:
(b) (i) and (iii)

Question 4.
Soil erosion can be prevented by ______
(a) deforestation
(b) afforestation
(c) over growing
(d) removal of vegetation
Answer:
(b) afforestation

Question 5.
A renewable source of energy is:
(a) petroleum
(b) coal
(c) nuclear fuel
(d) trees
Answer:
(d) trees

Samacheer Kalvi 10th Science Guide Chapter 22 Environmental Management

Question 6.
Soil erosion is more where there is _______
(a) no rainfall
(b) low rainfall
(c) rainfall is high
(d) none of these
Answer:
(c) rainfall is high

Question 7.
An inexhaustible resources is:
(a) wind power
(b) soil fertility
(c) wild life
(d) all of the above
Answer:
(d) all of the above

Question 8.
Common energy source in village is ______
(a) electricity
(b) coal
(c) biogas
(d) wood and animal dung
Answer:
(d) wood and animal dung

Question 9.
Green house effect refers to:
(a) cooling of earth
(b) trapping of UV rays
(c) cultivation of plants
(d) warming of earth
Answer:
(d) warming of earth

Question 10.
A cheap, conventional, commercial and inexhaustible source of energy is _____
(a) hydropower
(b) solar energy
(c) wind energy
(d) thermal energy
Answer:
(b) solar energy

Question 11.
Global warming will cause
(a) raise in level of oceans
(b) melting of glaciers
(c) sinking of islands
(d) all of these
Answer:
(d) all of these

Question 12.
Which of the following statement is wrong with respect to wind energy?
(a) wind energy is a renewable energy
(b) the blades of windmill are operated with the help of an electric motor
(c) production of wind energy is pollution-free
(d) usage of wind energy can reduce the consumption of fossil fuels
Answer:
(b) the blades of windmill are operated with the help of the electric motor

Samacheer Kalvi 10th Science Guide Chapter 22 Environmental Management

V. Answer in a Sentence:

Question 1.
What will happen if trees are cut down?
Answer:
If trees are cut down it give rise to ecological problems like floods, drought, soil erosion, loss of wild life, extinction of species, imbalance of biogeochemical cycles, alternation of climatic conditions and desertification.

Question 2.
What would happen if the habitat of wild animals is disturbed?
Answer:
If the habitual wild animals disturbed, the biological diversity cannot be maintained and cannot promote economic activities, which generates revenue to the government.

Question 3.
What are the agents of soil erosion?
Answer:
Agents of soil erosion are high velocity of wind, air currents, flowing water, land slide, human activities like deforestation, farming and mining overgrazing by cattle.

Question 4.
Why fossil fuels are to be conserved?
Answer:
Like fossil fuels, accumulation is a very slow process and takes a very long period, and in order to preserve them for a future generation, fossil fuels are to be conserved.

Question 5.
Solar energy is a renewable energy. How?
Answer:
Solar energy is the energy obtained from the sun. This energy resources is available in unlimited amount in nature and it can be renewed over a short period of time, inexpensive and can be harvested continuously.

Question 6.
How are e-wastes generated?
Answer:
E-wastes are generated from spoiled, outdated, non-repairable electrical and electronic devices.

VI. Short Answer Questions

Question 1.
What is the importance of rainwater harvesting?
Answer:

  1. Overcome the rapid depletion of ground water levels.
  2. To Meet the increase demand of water.
  3. Reduces flood and soil erosion.
  4. Water stored in ground is not contaminated by human and animal wastes and hence can be used for drinking purpose.

Question 2.
What are the advantages of using biogas?
Answer:
The advantages of using biogas are as follows:

  • It burns without smoke, causing less pollution.
  • It is an excellent way to get rid of organic wastes like bio-waste and sewage material.
  • The leftover slurry is good manure rich in nitrogen and phosphorus.
  • It is safe and convenient to use.
  • It can reduce the number of greenhouse gases emitted.

Question 3.
What are the environmental effect caused by sewage?
Answer:
Sewage water results in agricultural contamination and environmental degradation, pollute the water resources.

Question 4.
What are the consequences of deforestation?
Answer:
The contaminants can harm animals and damage the food chain.

  • Deforestation becomes a threat to the economy, quality of life and future of the environment.
  • Loss of many forests.
  • It gives rise to ecological problems like floods, drought, soil erosion, loss of wildlife, extinction of species, imbalance of biogeochemical cycles, alteration of climatic conditions and desertification.

Samacheer Kalvi 10th Science Guide Chapter 22 Environmental Management

VII. Long Answer Questions:

Question 1.
How does rainwater harvesting structures recharge groundwater?
Answer:
Recharge pit: In this method, the rainwater is first collected from the roof tops or open spaces and is directed into the percolation pits through pipes for filtration. After filtration the rainwater enters the recharge pits or ground wells.

People living in rural areas adopt a variety of water collecting methods to capture and store as rain water. Some of the methods used are-
(i) Digging of tanks or lakes (Eris) : It is one of the traditional water harvesting system in Tamil Nadu. Eris are constructed in such a way that if the water in one eri overflows, it automatically gets diverted to the eri of the next village, as these eris are interconnected.

(ii) Ooranis : These are small ponds to collect rainwater. The water is used for various domestic purposes (drinking, washing and bathing). These ponds cater the nearby villages.
Samacheer Kalvi 10th Science Guide Chapter 22 Environmental Management 2

Question 2.
How will you prevent soil erosion?
Answer:
The following are the methods to prevent soil erosion:

  • Retain vegetation cover, so that soil is not exposed.
  • Cattle grazing should be controlled.
  • Crop rotation and soil management improve soil organic matter.
  • Runoff water should be stored in the catchment.
  • Reforestation, terracing and contour ploughing.
  • Wind speed can be controlled by planting trees in the form of a shelterbelt.

Question 3.
What are the sources of solid wastes? How are solid wastes managed?
Answer:
Solid wastes mainly include municipal wastes, hospital wastes, industrial wastes and e-wastes etc. The solid wastes are dumped in the soil which results in landscape pollution.

Solid-waste management involves the collection, treatment and proper disposing of solid material that is discarded from the household and industrial activities.

Methods of solid wastes disposal:

  1. Segregation : It is the separation of different type of waste materials like biodegradable and non biodegradable wastes.
  2. Sanitary landfill : Solid wastes are dumped into low lying areas. The layers are compacted by trucks to allow settlement. The waste materials get stabilised in about 2-12 months. The organic matter undergoes decomposition.
  3. Incineration : It is the burning of nonbiodegradable solid wastes (medical wastes) in properly constructed furnace at high temperature.
  4. Composting : Biodegradable matter of solid wastes is digested by microbial action or earthworms and converted into humus.

Recycling of wastes:

  1. Papers from old books, magazines and newspapers are recycled to produce papers in papermills.
  2. Agricultural wastes like coconut shells, jute cotton stalk, bagasse of sugarcane can be used to make paper and hard board. Paddy husk can be used as livestock fodder.
  3. Cowdung and other organic wastes can be used in gobar gas plant to provide biogas and manure for fields. The 3R approach such as Reduce, Reuse and Recycle may be followed for effective waste management.

Question 4.
Enumerate the importance of forest.
Answer:

  • Forests are an important component of our environment.
  • There are microorganisms, flowering plants, shrubs, climbers and dense trees in the forest.
  • Forests provide a vast habitat for wild animals.
  • Forests help for the economic development of our country.
  • Forests are the source for a wide range of renewable natural resource.
  • Forests provide wood, food, fodder, fibre and medicine.
  • They act as a carbon sink, regulate climatic conditions, increase rainfall and reduce global warming.
  • The natural hazards like flood and landslides are prevented.
  • Wildlife is protected.
  • It acts as a catchment for water conservation.
  • Forests maintain ecological balance.

Samacheer Kalvi 10th Science Guide Chapter 22 Environmental Management

Question 5.
What are the consequences of soil erosion?
Answer:
The effects of soil erosion leads to loss of fertility of land, humus and nutrient. It leads to increased pollution, sedimentation in streams and rivers. Degraded lands able to hold water which can worsen flooding.

Question 6.
Why is the management of forest and wildlife resource considered as a challenging task?
Answer:
The management of forest and wildlife resource is considered as a challenging task because,

  • Due to deforestation, there is a lack of oxygen.
  • People kill animals, for making cloth designs so it harms the wildlife.
  • There is a lack of public awareness.
  • There are global warming and climate change.
  • Water scarcity and changes in rainfall pattern.
  • People kill animals and cut down trees, for economic benefit.
  • Poaching.
  • Forests cannot be irrigated like fields they depend on rain.
  • Changes in rainfall pattern, affect the development of forests and may lead to destruction.

VIII. Assertion and Reasoning:

In each of the following question a statement of assertion(A) is given and a corresponding statement of reason (R). Of the four statements given below mark the correct answer.
Question 1.
Assertion (A): Rainwater harvesting is to collect and store rain water.
Reason (R): Rainwater can be directed to recharge the underground water source.
(a) Both Assertion and Reason are true and Reason is correct explanation of Assertion.
(b) Both Assertion and Reason are true but Reason is not the correct explanation of Assertion.
(c) Assertion is true but Reason is false.
(d) Both Assertion and Reason are false.
Answer:
(a) Both Assertion and Reason are true and Reason is correct explanation of Assertion.

Question 2.
Assertion (A): Energy efficient bulbs like CFL must be used to save electric energy.
Reason (R): CFL bulbs are costlier than ordinary bulbs, hence using ordinary bulbs can save our money.
(a) Both assertion and reason are true and reason is correct explanation of assertion.
(b) Both Assertion and Reason are true but Reason is not the correct explanation of Assertion.
(c) Assertion is true but Reason is false.
(d) Both Assertion and Reason are false.
Answer:
(b) Both Assertion and Reason are true but Reason is not the correct explanation of Assertion.

IX. Higher Order Thinking Skills: (HOTS)

Question 1.
Although coal and petroleum are produced by degradation of biomass, yet we need to conserve them. Why?
Answer:
The formation of coal and petroleum is a very slow process and takes very long period of time for renewal. Moreover coal is uses for generation of electricity’ petroleum is used to run automobile, trucks, trains, ships and aeroplane. So we need to conserve them as they get exhausted.

Question 2.
What are the objectives for replacing non-conventional energy resources from conventional energy resources?
Answer:

  • Non-conventional energy resources can be replenished quickly.
  • Hydrocarbons are formed over a period of thousands of years when the remains of dead plants and animals are buried inside the Earth.
  • Burning coal and oil results in air pollution.
  • Conserve fossil fuels, using an alternate source of energy, when possible.
  • Wise utilization of non-renewable natural resources.

Samacheer Kalvi 10th Science Guide Chapter 22 Environmental Management

Question 3.
Why is the Government imposing ban on the use of polythene bags and plastics? Suggest alternatives. How is this ban likely to improve the environment?
Answer:

  1. It is non-biodegradable material which cause environmental pollution. It is harmful to wild life and marine life. It is very hard to clean or remove from environment.
  2. Alternatives to plastic bag are jute or canvas bags, paper bags.
  3. It control the pollution and clean the environment and make it better’ place to live for all organism.

X. Value-Based Questions:

Question 1.
Why is it not possible to use solar cells to meet our energy needs? State three reason to support your answer.
Answer:

  • The installing cost of solar cell panel is high, as the silicon wafer is very expensive and also the silver used in connecting solar cells.
  • D.C electricity is produced. To operate any A.C device, this D.C. has to be connected in, as by using an inverter.
  • The efficiency of energy conversion is low as compared to other means of generating electricity.

Question 2.
How would you dispose the following wastes?
(a) Domestic wastes like vegetable peels
(b) Industrial wastes like metallic cans
Can the disposal protect the environment? How?
Answer:
(a) Domestic waste like vegetable peels can be disposed by composting where solid wastes is digested by microbial action or earthworms and converted into humus.

(b) The metallic ions melt into molten aluminium this removes the coating and inks that may be present on the aluminium. The aluminium is then made into large blocks which is used to make other products.

Question 3.
List any three activities based on the 3R approach to conserve natural resources.
Answer:

  • Integrated solid waste management is based on the 3R approach. (Reduce, Reuse and Recycle).
  • 3R is aimed at the management of solid waste from all waste generating sectors.
  • 3R helps to minimize the amount of wastes from generation to disposal.

Samacheer Kalvi 10th Science Guide Chapter 22 Environmental Management

Samacheer Kalvi 10th Science Environmental Management Additional Important Questions and Answers

I. Choose the correct answers:

Question 1.
The best way to dispose waste is by:
(a) Making a paste for all domestic waste and putting them in a river.
(b) Separating biodegradable and non biodegradable before disposing in bins.
(c) Throw the waste an round side
(d) Dumping all domestic waste is better bin.
Answer:
(b) Separating biodegradable and non biodegradable before disposing in bins.

Question 2.
The solar energy which falls on the atmosphere reaches the Earth’s surface ______
(a) a little less than 42%
(b) more than 60%
(c) more than 52%
(d) a little less than 47%
Answer:
(d) a little less than 47%

Question 3.
Chipko Andolan is associated with
(a) Protesting against pasting of posters on walls.
(b) Saving money
(c) Using more postal stamps.
(d) Saving trees.
Answer:
(d) Saving trees.

Question 4.
The technique to harness the water energy is _______
(a) hydropower
(b) electrical energy
(c) tidal energy
(d) hydraulic fracturing
Answer:
(a) Hydropower

Question 5.
Conservation of wild life includes:
(a) Preventing poaching of animals
(b) Construction of National parks, Sanctuaries
(c) Ban on trading endangered species
(d) All the above
Answer:
(d) All the above

Question 6.
Select the eco-friendly activity among the following:
(a) Using car for transportation.
(b) Using polybags for shopping
(c) Using dyes for colouring clothes
(d) Using windmills to generate power for irrigation
Answer:
(d) Using windmills to generate power for irrigation

Question 7.
Pick the right combination of terms which has no fossil fuel.
(a) Wind, Ocean, Coal
(b) Kerosene, Wind, tide
(c) Wind, Wood, Sun
(d) Petroleum, Wood, Sun
Answer:
(c) Wind, Wood, Sun

Question 8.
Ground water will not be depleted due to:
(a) Afforestation
(b) Thermal power plants
(c) Loss of forest and decreased rainfall
(d) Cropping of high water demanding crops
Answer:
(a) Afforestation

Samacheer Kalvi 10th Science Guide Chapter 22 Environmental Management

Question 9.
Select the wrong statement:
(a) Forests provide variety of products
(b) Forests have greater plant diversity
(c) Forests do not conserve soil
(d) Forests conserve water
Answer:
(c) Forests do not conserve soil

Question 10.
The important messages conveyed by the ‘chipko movement’ is:
(a) To improve the community in forest conservation efforts.
(b) To ignore the community in forest conservation efforts.
(c) To cut down forest trees for developmental activities
(d) Preserves the natural ecosystem in the area.
Answer:
(a) To improve the community in forest conservation efforts.

II. Fill in the blanks:

1. Automobiles are largest source of ……… pollution in cities.
2. The first movement against tree felling was fought in chamoli district name ……….
3. ………. National park was the first in India.
4. Removal of upper layer of soil by wind and water is called ……..
5. The white marble of ……….. became yellow due to air pollution.
6. Arrangement of many solar cells side by side connected to each other is ……..
7. Gas produced by the decomposition of animal and plant waste in the absence of oxygen is ……….
8. The fuel extracted by a technique called ………… from the rock.
9. The World’s largest and tallest wind turbine is situated in …………
10. ………… Dam is constructed by King Karikala Chola.
Answer:
1. air
2. Chipko movement
3. Jim Corbett
4. soil erosion
5. Taj Mahal
6. Solar panel
7. Gobar gas
8. hydraulic fracturing
9. Hawaii
10. Kallanai

III. Assertion and Reason:

Question 1.
Assertion (A): Natural habitats of plants and animals should not be destroyed.
Reason (R): This is necessary for the conservation of biotic resources.
(a) Both Assertion and Reason are true and Reason is correct explanation of Assertion.
(b) Both assertion and reason are true but reason is not the correct explanation of assertion.
(c) Assertion is true but reason is false.
(d) Both assertion and reason are false.
Answer:
(a) Both Assertion and Reason are true and Reason is correct explanation of Assertion.

Samacheer Kalvi 10th Science Guide Chapter 22 Environmental Management

Question 2.
Assertion (A): To prevent hunting is not wildlife conservation in the real sense.
Reason (R): Some animals may multiply to the extent that they exhaust the food supply.
(a) Both assertion and reason are true and reason is correct explanation of assertion.
(b) Both assertion and reason are true but reason is not the correct explanation of assertion.
(c) Assertion is true but reason is false.
(d) Both assertion and reason are false.
Answer:
(b) Both assertion and reason are true but reason is not the correct explanation of assertion.

IV. Match the following:

Samacheer Kalvi 10th Science Guide Chapter 22 Environmental Management 3
Answer:
A. (iii)
B. (i)
C. (v)
D. (ii)
E. (iv)

V. State whether True or False. Correct the statements which are false:

  1. The devices used for harnessing sun energy is wind mill.
  2. Liquefied petroleum gas is obtained from petroleum.
  3. Harnessing the energy from flowing water to produce electricity is hydro power.
  4. 12% of e-wastes are from computer components.
  5. LED bulbs consume more electrical energy.

Answer:

  1. False – The devices used for harnessing wind is wind mill.
  2. True
  3. True
  4. False – 12% of e-wastes are from telecommunication components
  5. False – LED bulbs consume less electrical energy.

VI. Answer in a word or sentence:

Question 1.
Define Conservation.
Answer:
Proper utilization and management of nature and its resources in conservations.

Question 2.
What are the ways to sustain our resources?
Answer:
Some of the ways to sustain continuous use of resources are practices to utilise energy efficiently avoid wastage of water, avoid usage of Plastics and other non-biodegradable materials and to take care for the environment.

Samacheer Kalvi 10th Science Guide Chapter 22 Environmental Management

Question 3.
Suggest any two activities in daily life which are eco-friendly.
Answer:
Carrying jute or canvas bags for shopping instead of plastic bags.
Switch off electrical and electronic devices when not in use.

Question 4.
Name four substances that can be recycled.
Answer:
Newspaper, PET plastic bottles, steel can glass containers.

Question 5.
List any two common methods by which solid wastes of urban areas are disposed off.
Answer:

  1. Segregation of waste into biodegradable and non-biodegradable.
  2. Solid wastes are dumped into low lying areas.

Question 6.
What is chipko movement?
Answer:
The chipko movement was a non-violent that was aimed to protect and conserve the tree by the villagers of chamoli district of uttar pradesh.

Question 7.
Give the reason for decline in wildlife population.
Answer:
Over exploitation and shrinking of forest cover areas are the reason for animal extinction and verge of extinction.

VII. Short Answer Questions:

Question 1.
What is conservation? Why should we conserve natural resources?
Answer:
Proper utilization and management of nature and its resources are termed as conservation. It is important to conserve the natural resources carefully, to preserve it for future generations. We have to build a sustainable world, which should last forever.

Samacheer Kalvi 10th Science Guide Chapter 22 Environmental Management

Question 2.
How can you as an individual contribute to the management of coal and petroleum.
Answer:

  1. Use of coal and petroleum as a source of energy should be minimised.
  2. Use of CNG or LPG as fuels in automobiles.
  3. Renewable sources of energy like solar power, hydro power, wind energy, tidal energy should be used.

Question 3.
What are the methods to conserve the forest?
Answer:

  • Afforestation: Planting and protecting trees which help in the restoration of green cover is called the afforestation programme. Destruction of trees should be avoided.
  • Social forestry programme: Active participation of the public and utilization of common land, to produce firewood, fodder and timber for the benefit of the rural community.
  • Forest Conservation through Laws: Adopting laws and policies, to conserve and protect forests through National Forest Policy,

Question 4.
List the wild life conservation Initiatives in India.
Answer:

  1. Project Tiger and Project Elephant has been launched in 1973 and 1992 respectively.
  2. Crocodile Conservation Project was launched in 1976.
  3. Sea Turtle Conservation Project was launched in 1999.
  4. Indian Rhino Vision 2020 is to conserve at least 3000 greater one-homed rhinos in Assam, India by 2020.

Question 5.
What are the steps to be taken to conserve coal and petroleum resources?
Answer:

  • If electricity is saved, it will, in turn, reduce the use of coal.
  • Using bicycles for covering short distances instead of using cars, scooters or motorcycles.
  • Using pressure cooker can reduce the consumption of kerosene and LPG, during cooking food.
  • Solar cooker and solar heaters can be used wherever possible.
  • Motor vehicles should be designed with fuel-efficient engines to increase efficiency and also to reduce pollution.

Question 6.
What are the advantages of solar energy?
Answer:

  1. It is available in abundance in our country and is free of cost.
  2. It is a renewable source of energy.
  3. It can be used for generating electricity or heat.
  4. It does not cause pollution.

VIII. Long Answers Questions:

Question 1.
(a) What are the aims of wildlife management?
(b) What is the provision of the wildlife protection act?
Answer:
(a) The main aim of wildlife conservation are:

  • To control and limit exploitation of species.
  • To preserve the plants and animals from extinction.
  • Maintenance of threatened species and protect species which are on the verge of extinction.
  • Preserve the endangered species.
  • To study the ecological relationship of the plants and animals in natural habitat.
  • Hunting and poaching should be prohibited.
  • Establishment of national parks, wildlife sanctuaries, protected areas and biosphere reserves.

(b) The provisions of the wildlife protection act:

  • Prohibit killing and hunting of specified animals.
  • Constitute sanctuaries, national parks and closed areas for wildlife conservation.
  • Special schemes for the preservation of endangered species.
  • Constitute central zoo authority and recognition of zoos.
  • Restrict, regulate or prohibit trade in wild animals and products obtained from them.

Samacheer Kalvi 10th Science Guide Chapter 22 Environmental Management

Question 2.
Give the various steps to conserve non-renewable resource.
Answer:
It is necessary to conserve or save coal and petroleum resources for the future use, which can be done by reducing their consumption.

  1. If electricity is saved, it will intum reduce the use of coal.
  2. Using bicycle for covering short distances instead of using cars, scooters or motorcycles.
  3. Using pressure cooker can reduce the consumption of kerosene and LPG while cooking food. Solar cooker and solar heaters can be used wherever possible.
  4. Motor vehicles should be designed with fuel efficient engines to increase efficiency and also reduce air pollution.

Question 3.
Write notes for the following:
(a) Solar cells
(b) Solar panel
(c) Solar cooker and
(d) Solar thermal power plant
Answer:
(a) Solar cells: Solar cells are called photovoltaic devices, which are made up of silicon, that converts sunlight directly into electricity. Solar cells produce electricity, without polluting the environment. No harmful gases, no burning and no wastes are produced.

  • It can be used for street lighting, traffic signals, water pumping and battery charging system, etc.
  • It is used in artificial satellites and space probes.
  • It provides radio and TV transmission to remote areas.
  • It is used in calculators, electronic toys and watches.

(b) Solar panel: Arrangement of many solar cells side by side connected to each other is called solar panel. The capacity to provide electric current is much increased in the solar panel, but the process of manufacture is very expensive.

(c) Solar cooker: Solar cooker consists of an insulated metal box or wooden box, which is painted from inside, so as to absorb maximum solar radiations. A thick glass sheet forms the cover over the box. The reflector is the piano mirror, which is attached to the box. The food is cooked by energy radiated by the Sun.

(d) Solar thermal power plant:
In solar thermal power plants, many solar panels are used to concentrate sun rays, to heat up water into steam. The steam is used to run the turbines to produce electricity. The solar energy is available in our country at free of cost, do not cause any pollution and is a renewable source of energy.

Question 4.
Explain the tidal energy with its advantages.
Answer:
Tidal energy is the energy obtained from the movement of water due to ocean tides. Tides are the rise and fall of sea levels caused by the combined effects of the gravitational forces exerted on the oceans of the earth.

A tidal stream is a fast flowing body of water created by tides. Turbines are placed in tidal streams. When the tides hit the turbine, the turbine rotates and converts the tidal energy into electric energy.

Advantages of tidal energy:

  1. Tidal energy does not produce any pollution.
  2. It does not use any fuel and does not produce any waste.
  3. Tides are predictable, so tidal energy can be produced at any time.
  4. Water is denser than air and therefore can generate electricity at lower speeds than wind turbines.

Question 5.
Explain the convention method of waste water treatments.
Answer:
The conventional wastewater treatment methods involve the following steps (a) Pre-screening (b) Aeration (c) Sludge Management and (d) Water Reuse.
(a) Pre-screening : Wastewater generated from domestic and industrial activities is screened to remove soil and solid particulates.

(b) Aeration : Screened wastewater is then pumped to an aeration tank. Here the microbial contaminants are removed by the biological degradation that occurs in the presence of air.
Sedimentation process : In this process, the solid particles in suspension form are allowed to settle. The particles that settle out from the suspension is known as sludge.

(c) Sludge removal : The sludge generated by the degradation process is transferred periodically from the tank for safe disposal.
Disinfection : Chlorination and ultraviolet (UV) radiation of treated water is required to remove any microorganism contamination.

(d) Water recycling : The water will then be supplied for domestic or industrial purposes.

Samacheer Kalvi 10th Science Guide Chapter 22 Environmental Management

IX. Hot Questions:

Question 1.
Name the movement aimed at the protection and conservation of trees. In which district was it originated?
Answer:
Chipko movement at Uttarkhand.

Question 2.
Name any two wildlife conservation initiatives in India.
Answer:

  • Crocodile conservation project
  • Indian Rhino vision 2020
  • Sea Turtle conservation

X. Value Based Question:

Question 1.
The over exploitation of natural resources leads to decline of natural resources.
(a) What will be the effects decline of natural resources.
(b) How can be prevent it?
Answer:
(a) Decline of natural resources leads to energy crisis and disturbance in ecological balance.
(b) It can be prevented by using non-conventional energy resources.

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