Samacheer Kalvi 10th Science Solutions Chapter 22 Environmental Management

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Tamilnadu Samacheer Kalvi 10th Science Solutions Chapter 22 Environmental Management

Samacheer Kalvi 10th Science Environmental Management Textual Evaluation Solved

I. Fill in the blanks.

Question 1.
Deforestation leads to ______ in rainfall.
Answer:
Reduction

Question 2.
Removal of soil particles from the land is called ______
Answer:
Soil erosion

Question 3.
Chipko movement is initiated against ______
Answer:
the cutting down of trees

Question 4.
______ is a biosphere reserve in Tamilnadu.
Answer:
Nilgiris

Question 5.
Tidal energy is ______ type of energy.
Answer:
Non-conventional or renewable

Question 6.
Coal, petroleum and natural gas are called ______ fuels.
Answer:
Fossil

Question 7.
______ is the most commonly used fuel for the production of electricity.
Answer:
Coal

II. State whether True or False. If false, write the correct statement:

Question 1.
Biogas is a fossil fuel.
Answer:
False
Correct statement: Biogas is the mixture of methane, hydrogen sulphide, carbon-di-oxide and hydrogen.

Question 2.
Planting trees increase the groundwater level.
Answer:
True

Question 3.
Habitat destruction caused loss of wildlife.
Answer:
True

Question 4.
Nuclear energy is renewable energy.
Answer:
False
Correct statement: Nuclear energy is a non-renewable energy source. The material used in nuclear plants is not renewable.

Question 5.
Overgrazing prevents soil erosion.
Answer:
False
Correct statement: During overgrazing, most of the plants are eaten up. If the plants or vegetation is retained, the soil is not exposed. Soil erosion occurs due to overgrazing.

Question 6.
Poaching of wild animals is a legal act.
Answer:
False
Correct statement: Poaching should be prohibited.

Question 7.
The national park is a protected park.
Answer:
True

Question 8.
Wildlife protection act was established in 1972.
Answer:
True

III. Match the following:

Question 1.

Column A	Column B
1. Soil erosion	(a) energy saving
2. Bio-gas	(b) acid rain
3. Natural gas	(c) removal of vegetation
4. Greenhouse gas	(d) renewable energy
5. CFL bulbs	(e) CO2
6. Wind	(f) non-renewable energy
7. Solid waste	(g) lead and heavy metals

Answer:

1. (c) Removal of vegetation
2. (d) Renewable energy
3. (f) Non-renewable energy
4. (e) CO₂
5. (a) energy saving
6. (b) acid rain
7. (g) Lead and heavy metals

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 is _________
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:
(d) i, ii 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

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

Question 7.
An inexhaustible resources is _______
(a) wind power
(b) soil fertility
(c) wildlife
(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.
The greenhouse 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:
(c) wind energy

Question 11.
Global warming will cause _______
(a) raise in the 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 wind mill are operated with the help of 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 wind mill are operated with the help of electric motor

V. Answer in a Sentence.

Question 1.
What will happen if trees are cut down?
Answer:
Soil erosion occurs and ecological imbalance takes place if trees are cut down.

Question 2.
What would happen if the habitat of wild animals is disturbed?
Answer:
If the habitat of wild animal is disturbed it leads to extinction of animals or on the verge of extinction.

Question 3.
What are the agents of soil erosion?
Answer:
The high velocity of wind, air currents, flowing water, landslide, human activities such as deforestation, farming and mining, and overgrazing by cattle are the agents of soil erosion.

Question 4.
Why fossil fuels are to be conserved?
Answer:
The formation of fossil fuels is a very slow process and takes very long period of time for renewals so fossil fuels are to conserved.

Question 5.
Solar energy is renewable energy. How?
Answer:
Solar energy is renewable, free source of energy, that is sustainable and totally inexhaustible.

Question 6.
How are e- wastes generated?
Answer:
e-wastes are spoiled, out dated, non-repairable, electrical and electronic devices like computer components electronic and electrical appliances.

VI. Short Answer Questions

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

• overcome the rapid depletion of groundwater levels.
• To meet the increased demand for water.
• Reduces flood and soil erosion.
• 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:

1. It bums without smoke and therefore causes less pollution.
2. An excellent way to get rid of organic wastes like bio-waste and sewage material.
3. Left over slurry is a good manure rich in nitrogen and phosphorus.
4. It is safe and convenient to use.
5. It can reduce the amount of greenhouse gases emitted.

Question 3.
What is the environmental effect caused by sewage?
Answer:

• Sewage is the leading polluter of water resources in India.
• Different species of fishes are killed.
• Contaminated water can cause diseases such as e-coli, diarrhoea and hepatitis A.

Question 4.
What are the consequences of deforestation?
Answer:
Deforestation gives rise to ecological problems like floods, drought, soil erosion, loss of wild life, extinction of species, imbalance of biogeochemical cycles, alteration of climatic conditions and desertification.

VII. Long Answer Questions

Question 1.
How does rainwater harvesting structures recharge groundwater?
Answer:
Rainwater harvesting is a technique of collecting and storing rainwater for future use. The main purpose of rainwater harvesting is to make the rainwater percolate under the ground, so as to recharge ‘groundwater level’.

Methods of rainwater harvesting
(i) Rooftop rainwater harvesting: The rainwater that falls on the roof of the houses, apartments and commercial buildings, etc, is collected and stored in the surface tank and is used for domestic purpose.

(ii) Recharge pit: The collected rainwater is directed into the percolation pits through pipes for Alteration. After Alteration, the rainwater enters the recharge pits or ground wells.

• Digging of tanks or lakes (Eris): Eris is 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.
• Ooranis: These are small ponds to collect rainwater. They are used for various domestic purposes.

Question 2.
How will you prevent soil erosion?
Answer:

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

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:

• Segregation: It is the separation of different type of waste materials like biodegradable and non-biodegradable wastes.
• 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.
• Incineration: It is the burning of non-biodegradable solid wastes (medical wastes) in the properly constructed furnace at high temperature.
• Composting: Biodegradable matter of solid wastes is digested by microbial action or earthworms and converted into humus.

Question 4.
Enumerate the importance of forest.
Answer:
Forests are an important component of our environment and are dominated by microorganisms, flowering plants, shrubs, climbers, dense trees and provide a vast habitat for wild animals. Forests also contribute to the economic development of our country. Forests are vital for human life, it is a source for a wide range of renewable natural resource. They provide wood, food, fodder, fibre and medicine.

Forests are major factor of environmental concern. They act as a carbon sink, regulate climatic conditions, increase rainfall, reduce global warming, prevent natural hazards like flood and landslides, protect wildlife and also act as catchments for water conservation. They also play a vital role in maintaining ecological balance.

Question 5.
What are the consequences of soil erosion?
Answer:
The consequences of soil erosion are as follows:

• It has led to increased pollution and sedimentation in streams and rivers.
• Clogging the waterways and causing a decrease in fish species.
• Degraded lands often have less ability to hold on to water.
• Topsoil is removed.
• Topsoil quality is reduced.
• No medium crops to grow in soil with poor quality.
• Use of artificial fertilizers.
• Disrupts ecosystem.

Question 6.
Why is the management of forest and wildlife resource considered as a challenging task?
Answer:
People would consider forest is a source of raw materials for the factories and industries, and utilise it for development of human without considering about other organism. There are many stake holders of forest. They are those people who are directly or indirectly involved in forest. Management of forest and called life has to take into account the interest of all stake holders which become a challenging task.

VIII. Assertion and Reasoning Questions

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.
(a) Both assertion and reason are true and the reason is the correct explanation of assertion.
(b) Both assertion and reason are true but the reason is not the correct explanation of assertion.
(c) Assertion is true but the reason is false.
(d) Both assertion and reason are false.

Question 1.
Assertion: Rainwater harvesting is to collect and store rainwater.
Reason: Rainwater can be directed to recharge the underground water source.
Answer:
(a) Both assertion and reason are true and the reason is the correct explanation of assertion.

Question 2.
Assertion: Energy-efficient bulbs like CFL must be used to save electric energy.
Reason: CFL bulbs are costlier than ordinary bulbs, hence using ordinary bulbs can save our money.
Answer:
(c) Assertion is true but the reason is false.

IX. Higher Order Thinking Skills (HOTS) Questions

Question 1.
Although coal and petroleum are produced by the degradation of biomass, yet we need to conserve them. Why?
Answer:

• The coal and petroleum reserves can get exhausted, if we use them at a rapid rate.
• The formation of fossil fuel is a very slow process and takes a very long time for renewal.
• It is necessary to conserve the resource, for the future generation, by reducing their consumption.

Question 2.
What are the objectives for replacing non-conventional energy resources from conventional energy resources?
Answer:
Non conventional energy resources are non-polluting renewable sources which are environmentally clean. It is available in unlimited amount in nature and they can be renewed over a short period of time inexpensive and can be harvested continuously.

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

• Plastics pollute on land, rivers, ponds and all water bodies and soil, etc.
• Burning of plastic in open air leads to environmental pollution, due to the release of poisonous gas.
• The accumulation of plastic bags and plastics prevent the seeping of water into the Earth, which brings down the levels of groundwater.
• Plastic bags can travel long distances by wind and water. They litter our landscapes and water bodies.

Alternatives:

• Bring your own containers and bags to buy things from the shop.
• Use paper wraps or compostable bags with cloth or brown paper.

Improvement of the environment on plastic ban:

• Improve the health of individuals.
• Driving to innovate alternatives.
• Plastic pollution reduced.
• The nation is safe.

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 to your answer.
Answer:
In solar cells, the solar panel convert solar energy into electricity, which stored in storage battery. The storage battery gives direct current, which is to be converted into alternating current by an suitable appliances before it can be used to run various, devices. So, it increases the cost of using panels as the source of energy.

In the solar cells the energy is obtained only during the day, when the sun shines. So the solar cells is not used to meet our energy needs.

Question 2.
How would you dispose of the following wastes?

1. Domestic wastes like vegetable peels
2. Industrial wastes like metallic cans

Can the disposal protect the environment? How?
Answer:

1. Domestic wastes have to be thrown out with the trash.
2. Do vermiform composting system for vegetable wastes which can be used as a manure. Industrial wastes like metallic cans can be recycled.

Question 3.
List any three activities based on 3R approach to conserve natural resources.
Answer:
Recycling : Using recycled material of glass plastic, paper, metal etc.
Reuse : Repeating use of items.
Reduce : Avoid the use of materials which increases the solid waste.
Use of public transport instead of personal transport to reduce to consumption of fuel. Use of materials such as paper should be preferred.

Textbook Activities Solved

Question 1.
Collect information regarding the
(i) Tehri Dam project
(ii) Sardar Sarovar Dam project
Answer:
(i) Tehri Dam project:
Tehri Dam is the highest dam in India and one of the highest in the world. It is a multi-purpose rock and earth-filled embankment dam on the Bhagirathi River near Tehri in Uttarakhand, India. It is the primary dam of the THDC India limited and the Tehri hydro-electric complex. The Tehri Dam withholds a reservoir for irrigation, municipal water supply and the generation of 1000 megawatts of hydroelectricity.

(ii) Sardar Sarovar dam project:
Sardar Sarovar Dam is a gravity dam on the Narmadha river near Navagam. It is a part of the Narmada valley project, a large hydraulic engineering project.
Benefits:

• Provides irrigation facilities.
• Drinking water supply.
• There are two powerhouses, red bed powerhouse and canal head powerhouse with a capacity of 1200 MW and 250 MW, respectively.
• It provides flood protection.
• Wildlife sanctuaries are maintained.
• Development of fisheries.
• Water supply for industries.
• Protection of conserved forests.

Samacheer Kalvi 10th Science Environmental Management Additional Questions Solved

I. Fill in the blanks.

Question 1.
______ is used for generation of _____, at thermal power plants.
Answer:
Coal, Electricity

Question 2.
Petroleum is refined to produce _____ and _____, which are used to run automobiles, trucks, trains and ships, etc.
Answer:
Petrol, Diesel

Question 3.
______ and ______ obtained from petroleum are used as domestic fuel.
Answer:
Kerosene, LPG

Question 4.
Solar energy is obtained from ______
Answer:
Sun

Question 5.
Solar cells convert sunlight directly into ______
Answer:
Electricity

Question 6.
_______ plants convert the kinetic energy of flowing water into electricity.
Answer:
Hydropower

Question 7.
The 3R approach such as _____, _____ and ______ may be followed to effective waste management.
Answer:
Reduce, Reuse and Recycle

Question 8.
_______ is a reserved area for the conservation of entire wildlife including plants and animals.
Answer:
National park

Question 9.
______ is a place reserved exclusively for the use of animals.
Answer:
Sanctuary

Question 10.
Unwanted, non-working and out-dated electronic products become ______
Answer:
e-waste

Question 11.
In India, the forests are classified into ______ forests and ______ forests.
Answer:
Reserved, Protected

Question 12.
The small ponds to collect rainwater is called ______
Answer:
Ooranis

II. Write true or false for the following statements. Correct the false statements:

Question 1.
Conservation of natural resources makes an important contribution to the social and economic development of the country.
Answer:
True

Question 2.
Overexploitation and shrinking of forest resulted, the increase of animals and the nourishment of wildlife.
Answer:
False
Correct statement: Overexploitation and shrinking of forest resulted, in animals becoming extinct, some are threatened and some are on the verge of extinction.

Question 3.
The potential energy possessed by the wind, due to lower speed, that can be converted into chemical power by wind turbines.
Answer:
False
Correct statement: The kinetic energy possessed by the wind is due to its high speed, that can be converted into mechanical power by wind turbines.

Question 4.
The main purpose of rainwater harvesting is to make the rainwater, run on its surface of Earth.
Answer:
False
Correct statement: The main purpose of rainwater harvesting is to make the rainwater, to percolate under the ground, so as to recharge the groundwater level.

Question 5.
The burning of non-biodegradable solid wastes (medical wastes) in the properly constructed furnace at high temperature is called electronic wastes.
Answer:
False
Correct statement: The burning of non-biodegradable solid wastes (medical wastes) in the properly constructed furnace at high temperature is called incineration.

III. Match the following:

Question 1.

1. Van Mahotsav	(a) Destruction of forests
2. Bombay Natural History Society	(b) Crude oil
3. Deforestation	(c) Photovoltaic devices
4. Erosion	(d) Afforestation programme
5. Solar cells	(e) Conservation of wildlife
6. Petroleum	(f) Removal of an upper layer of soil

Answer:

1. (d) Afforestation programme
2. (e) Conservation of wildlife
3. (a) Destruction of forests
4. (f) Removal of an upper layer of soil
5. (c) Photovoltaic devices
6. (b) Crude oil

IV. Choose the correct answer:

Question 1.
The new sources of energy are termed as _______
(a) fossil fuel
(b) Conventional energy resources
(c) Non-conventional sources of energy
(d) conservation
Answer:
(c) non-conventional sources of energy

Question 2.
Disposable plastic plates should not be used because:
(a) They are made of materials with light weight
(b) They are made of toxic materials.
(c) They are made of biodegradable materials.
(d) They are made of non-biodegradable materials.
Answer:
(d) They are made of non-biodegradable materials.

Question 3.
The other name for Biogas is ______
(a) Natural gas
(b) Nitrogen gas
(c) Gobar gas
(d) Shale gas
Answer:
(c) Gobar gas

Question 4.
Wildlife includes:
(a) Wild animals only
(b) Wild plants only
(c) Wild plants and animals
(d) All plants and animals
Answer:
(d) All plants and animals

Question 5.
E-wastes are generally called as _______
(a) garbages
(b) electronic waste
(c) decomposition
(d) solid wastes
Answer:
(b) electronic waste

V. Answer the following shortly.

Question 1.
Why should we conserve forests and wild life?
Answer:
We should conserve forest and wild life to preserve the biodiversity, so as to avoid the loss of ecological stability. Without proper management of forest and wild life, the quality of soil, the water sources, and even the amount of rainfall may be affected.

Question 2.
What are the effects of deforestation?
Answer:
Deforestation 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.

Question 3.
Name the organisation involved in wild life conservation.
Answer:
Organisations Involved in Conservation of Wildlife

1. Indian Board for WildLife (IBWL)
2. World Wildlife Fund (WWF) for Nature
3. World Conservation Union (WCN) ,
4. International Union for Conservation of Nature and Natural resources (IUCN)
5. Convention of International Trade in Endangered Species (CITES)
6. Bombay Natural History Society
7. Wild life Preservation Society of India, Dehradun

Question 4.
What are fossil fuels? How are they formed?
Answer:
The fossil fuels are petroleum, coal and natural gas. Due to the anaerobic decomposition of buried dead organisms, by a natural process over millions of years, energy-rich substances are formed. As the accumulating sediment layers produce heat and pressure, the remains of the organisms are gradually transformed into hydrocarbons.

Question 5.
Write the uses of solar cells.
Answer:

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

Question 6.
Write short notes about shale gas.
Answer:
Due to the compaction of small old rocks, which contain mud and minerals such as quartz and calcite, trapped beneath Earth’s surface and form the soft finely stratified sedimentary rock called shale. These rocks contain fossil fuels like oil and gas in their pores. This fuel is extracted by a technique called hydraulic fracturing.

Shale drilling could affect groundwater reserves, which can contaminate drinking water. It also affects the fertility of the soil. A million gallons of water is needed to break and release the shale gas which in turn can affect the fertility of the soil.
A million gallons of water is needed to break and release the shale gas, which in turn can affect the water table.

Question 7.
What is Tidal energy? What is it’s advantages?
Answer:
The energy obtained from the movement of water, due to ocean tides is called tidal energy. Tides are the rise and fall of sea level, caused by the combined effects of the gravitational force. 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:

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

Question 8.
How is electric energy conserved?
Answer:

• Use energy-efficient appliances to save electricity like compact fluorescent lamps (CFL), Light Emitting Diode [LED] bulbs and other electrical equipment.
• Switch off the lights and fans, television and other electrical appliances, when not in use.
• Switch off the mobile phone chargers when not in use.
• Use more off solar radiation. Solar water heating system can be used instead of electric geysers.
• Minimise the use of air conditioners.

Question 9.
What are the sources of e-waste? What is the environmental impact of e-waste?
Answer:
E-wastes are called electronic wastes, which includes the spoiled, outdated; non-repairable electrical and electronic devices. These wastes contain toxic metals like lead, cadmium, chromium and mercury, and also contains iron, copper, silicon, aluminium and gold, which can be recovered. The sources of e-wastes are:

• Electronic device: Computers, laptops, mobile phones, printers, monitors, televisions, DVD players, calculators, toys and sports equipment.
• Household electrical appliances: Refrigerators, washing machine, microwave oven, mixer, grinder and water heater, etc.
• Accessories: Printing cartridges, batteries and chargers.

Environmental impact of e-wastes:
Disposal of any kind of electrical and electronic devices without knowledge can become the landfill and water pollutants.
Electronic equipment contains many heavy metals such as lead and cadmium that can cause severe soil and groundwater pollution. E-waste dumping yards and the places, nearby are polluted and cause a severe health hazard.

Question 10.
What is the 3R approach of ineffective waste management?
Answer:
Reduce, Reuse and Recycle are the 3R approach for effective waste management. Reducing the amount of waste, we produce is the best way to help the environment. Buying products with minimum packaging, not borrowing things which we do not use often, starting a compost bin, saving energy and water by turning are ways to reduce. Reuse materials in their original form or pass those materials on to others, who could use them. Paper cardboard, metals, plastics and textiles, etc can be recycled. The compost or reuse of bio-degradable wastes is also a kind of recycling.

Question 11.
What are non-conventional energy resources? What does it include?
Answer:
The energy resources available in an unlimited amount in nature and they can be renewed over a short period of time, inexpensive and can be harvested continuously is called the non-conventional energy resources.

The non-conventional energy resources include biofuel, bio mass-energy, geothermal energy, water energy (hydroelectric energy and tidal energy), solar energy, wave energy and wind energy.

Question 12.
What is the composition of Bio-gas? How is it formed?
Answer:

• Bio-gas is the mixture of methane (75%), hydrogen sulphide, carbon dioxide and hydrogen.
• It is produced by the decomposition of animal wastes (cow dung) and plant wastes in the ‘ absence of oxygen.
• It is also commonly called as “Gobar gas”, as the starting material used is cow dung, which ~ means gobar in Hindi.

Question 13.
What are hydropower and hydropower electricity?
Answer:
Earth is covered with 71% of water. The technique to harness the water energy, from the flowing water is called the hydropower.

The electrical energy is derived from water flow and water falling from a height. In hilly areas, there is a continuous flow of water in large amounts falling from high slopes. The electricity produced by flowing water is called hydropower electricity.

VII. Answer the following in detail.

Question 1.
What are the aims of wildlife management?
Answer:
The main aim of wildlife conservation are:

1. To control and limit exploitation of species.
2. To preserve the plants and animals from extinction.
3. Maintenance of threatened species and protect species which are on the verge of extinction.
4. Preserve the endangered species.
5. To study the ecological relationship of the plants and animals in natural habitat.
6. Hunting and poaching should be prohibited.
7. Establishment of National parks, Wildlife sanctuaries, protected areas and Biosphere reserves.

Question 2.
Explain in detail the classification of energy resources.
Answer:
Energy resources can be classified as renewable and non-renewable.
(i) Non-renewable (exhaustible) energy resources:
The energy obtained from sources that cannot renew themselves over a short period of time is called non-renewable energy. They include coal, petroleum, natural gas and nuclear power. The conventional energy resources account for 90% of the world’s production of commercial energy and nuclear power account for 10%.

(ii) Renewable (inexhaustible) energy resources:
Renewable (inexhaustible) energy resources are available in the unlimited amount in nature and they can be renewed over a short period of time, inexpensive and can be harnessed continuously. These are called non-conventional energy resources, which include biofuel, biomass energy, geothermal energy, water energy (hydroelectric energy and tidal energy), solar energy, wave energy and wind energy.

Question 3.
Write a note an shale gas. Explain the environment impact of shale gas.
Answer:
Shale refers to the soft finely stratified sedimentary rock that is formed from the compaction of small old rocks containing mud and minerals – such as quartz and calcite, trapped beneath earth’s surface. These rocks contain fossil fuels like oil and gas in their pores.

The fuel is extracted by a technique called hydraulic fracturing (drilling or well boring of sedimentary rocks layers to reach productive reservoir layers).

Environmental concerns of shale gas:

1. Shale drilling could affect groundwater reserves, which can contaminate the drinking water resources and also affect the fertility of the soil.
2. Million gallons of water is needed to break and release the shale gas, which intum can affect the water table.

Question 4.
(a) How does windmill work?
(b) List out the uses of wind energy and the advantages of wind energy.
Answer:
(a) A windmill is a machine, that converts the energy of wind, into rotational energy by broad blade attached to the rotating axis. When the blowing air strikes the blades of the windmill, it exerts force and causes the blades to rotate. The rotational movement of the blades operate the generator and the electricity is produced. The energy output from each windmill is coupled together to get electricity on a commercial scale.

(b) The uses of wind energy are as follows:

• Generating electricity.
• Run water pumps and flour mills, etc.
• Rotatory motion of windmill is used to draw water from wells.

Advantages of wind energy:

• Wind energy is a free, eco-friendly and renewable source of energy.
• It does not cause pollution.
• Expenses on periodic maintenance are low when compared to the other power sources.

Question 5.
(a) What are the sources of sewage or wastewater?
(b) Expiate the methods which involve in conventional wastewater treatment.
Answer:
(a) The sources of sewage or wastewater involve:

• The domestic purpose or household activities
• Dye and textile industries
• Leather industries
• Sugar and breweries industries
• Paper and pulp industries

(b) The conventional wastewater treatment methods involve the following step:

• Pre-screening: Wastewater generated from domestic and industrial activities is screened to remove soil and solid particulates.
• Aeration: Screened wastewater is 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.
• 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.
• Water recycling: The water will then be supplied for domestic or industrial purposes.

VII. Higher Order Thinking Skills (HOTS) Questions

Question 1.
There are certain NGOs which ask people to donate their used clothes, toys, school books, house hold items. These NGOs segregate the collected items and distribute them to the needy people. What objectives do these NGOs fulfil by this initiatives?
Answer:
The objective behind this is Reuse and Recycle.

Question 2.
Name the national park, which was first established at Uttarakhand.
Answer:
Jim Corbett national park.

Question 3.
An environmentalist on your visit to your school suggested the use of 3R’s to same the environment. Explain the 3R’s.
Answer:
The 3R’s are Reduce, Reuse and Recycle.
Reuse : Instead of throwing thing away, try to find ways to use them again.
Recycle : Creating new product out of the materials from the old.
Reduce : It is the best way to help the environment by reducing the amount of waste you produce.

Question 4.
Where does India stand at the consumer of crude oil?
Answer:
India is the third-largest consumer of crude oil in the world after the United States and China.

Question 5.
Why does the white marble of Tajmahal become yellow?
Answer:
The Mathura oil refinery owned by Indian Oil Corporation presents around this area, which produces sulphur and nitrogen oxides. The white marble became yellow due to air pollution. The Government of India has set up emission standards around the monument to protect it from the damage.

Question 6.
Name the fourth oldest dam in the world? Where is it located?
Answer:
Kallanai Dam, which is also Called Grand Anicut, is the fourth oldest dam in the world. The dam is located on the river Kaveri, 20 km from the city of Tiruchirappalli.

Question 7.
Where is the world’s largest and tallest wind turbine located?
Answer:
The world’s largest and tallest wind turbine is situated in Hawai. One wind turbine can produce electricity for 300 homes.

Question 8.
Name the health effects of the following E-wastes.
Answer:

• Lead: Damages the central and peripheral nervous system. It also affects brain development in children.
• Chromium: Asthmatic bronchitis.
• Cadmium: Accumulates in kidney and liver; Neural damage.
• Mercury: Chronic damage to the brain and respiratory system.
• Plastics including polyvinyl chloride [PVC]: Burning produces, dioxin, which can cause developmental and reproductive problems and damage the immune system.