Samacheer Kalvi Class 10 Science Chapter 22 Environmental Management

Column I	Column II
A Soil erosion	(i) energy saving
B Bio gas	(ii) acid rain
C Natural gas	(iii) removal of vegetation
D Green house gas	(iv) renewable energy
E CFL bulbs	(v) CO₂
F Wind	(vi) non-renewable energy
G Solid waste	(vii) lead and heavy metals

Answer:
A. (iii) Soil erosion is the removal of vegetation.
B. (v) Biogas is mostly made of CO₂.
C. (vi) Natural gas is a non-renewable energy source.
D. (ii) Greenhouse gases cause acid rain.
E. (i) CFL bulbs are used for energy saving.
F. (iv) Wind is a renewable energy source.
G. (vii) Solid waste often contains lead and heavy metals. This matching helps connect environmental issues with their causes, effects, or solutions.
In simple words: Soil erosion means taking away plants. Biogas has CO₂. Natural gas cannot be remade quickly. Greenhouse gases lead to acid rain. CFL bulbs save power. Wind is energy that never runs out. Solid waste has heavy metals.

🎯 Exam Tip: Carefully read each item in Column I and find its most appropriate match in Column II. Consider the definitions, causes, and effects when making your choices.

IV. Choose The Correct Answer:

 

Question 1. Which of the following is / are a fossil fuel?
(a) (i) only
(b) (i) and (ii)
(c) (ii) and (iii)
(d) (i), (ii) and (iii)
Answer: (c) (ii) and (iii)
In simple words: The correct answer means that coal and petroleum are types of fossil fuels. These fuels come from very old living things.

🎯 Exam Tip: Remember that fossil fuels like coal and petroleum are formed over millions of years from dead organic matter.

 

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 options
Answer: (d) All of the options
In simple words: To manage waste better, you should first make less waste, then use things again if possible, and finally turn old items into new ones. All these steps help the environment.

🎯 Exam Tip: The "3R" approach (Reduce, Reuse, Recycle) is a fundamental principle of effective waste management. Always remember all three steps.

 

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)
In simple words: Cars release carbon monoxide and oxides of nitrogen, which are harmful gases. These gases pollute the air and are not good for our health.

🎯 Exam Tip: Know the main pollutants emitted by vehicle exhausts, as they are a common cause of air pollution.

 

Question 4. The main cause of soil erosion is:
(a) no rainfall
(b) afforestation
(c) over growing
(d) removal of vegetation
Answer: (d) removal of vegetation
In simple words: When plants and trees are removed, the soil becomes loose and can be easily washed or blown away. This is a major reason for soil erosion.

🎯 Exam Tip: Remember that plant cover holds soil in place, so removing it directly leads to soil erosion.

 

Question 5. A renewable source of energy is:
(a) petroleum
(b) coal
(c) nuclear fuel
(d) trees
Answer: (d) trees
In simple words: Trees are a renewable energy source because new ones can be planted to replace those that are used. Petroleum, coal, and nuclear fuel are all non-renewable resources.

🎯 Exam Tip: Understand that renewable resources can be replenished naturally over a relatively short period, while non-renewable ones are finite.

 

Question 6. Soil erosion is more where there is
(a) no rainfall
(b) low rainfall
(c) rainfall is high
(d) None of the options
Answer: (c) rainfall is high
In simple words: When a lot of rain falls quickly, it washes away the soil more easily. This means that soil erosion is worse in places with heavy rainfall.

🎯 Exam Tip: High intensity rainfall directly increases the force of water hitting the ground, leading to more soil runoff and erosion.

 

Question 7. An inexhaustible resource is:
(a) wind power
(b) fossil fuel
(c) wild life
(d) All of the options
Answer: (a) wind power
In simple words: Wind power is an inexhaustible resource because wind will always be present on Earth. Unlike fossil fuels, it will never run out.

🎯 Exam Tip: Inexhaustible resources are those that are available in unlimited quantities and will not be depleted by human use, such as solar, wind, and tidal energy.

 

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
In simple words: In many villages, people commonly use wood and dried animal dung for cooking and heating because they are easily available. These natural resources are essential for daily life in rural areas.

🎯 Exam Tip: Understand the difference between energy sources typically used in urban versus rural areas, considering availability and traditional practices.

 

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
In simple words: The greenhouse effect is when certain gases in the atmosphere trap heat, which makes the Earth warmer. This process helps keep our planet at a livable temperature, but too much warming can cause climate change.

🎯 Exam Tip: The greenhouse effect is a natural process, but human activities like burning fossil fuels can intensify it, leading to global warming.

 

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
In simple words: Wind energy is a good choice because it is cheap, common, used for business, and will never run out. It is a clean source of power.

🎯 Exam Tip: Focus on the combination of characteristics given in the question (cheap, conventional, commercial, inexhaustible) to identify the best match among the options.

 

Question 11. Global warming will cause
(a) raise in level of oceans
(b) melting of glaciers
(c) sinking of islands
(d) All of the options
Answer: (d) All of the options
In simple words: Global warming will lead to higher ocean levels, melting ice, and some islands going underwater. These are all serious changes to our planet.

🎯 Exam Tip: Remember the major consequences of global warming, as they are interconnected and impact many aspects of the environment.

 

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
In simple words: The wrong statement is that an electric motor runs the windmill blades. Actually, the wind itself moves the blades to make electricity. Wind energy is clean and renewable.

🎯 Exam Tip: Carefully read each option in "which statement is wrong" questions to identify the factual error. Windmills harness wind power directly.

V. Answer In A Sentence:

 

Question 1. What will happen if trees are cut down?
Answer: If trees are cut down, it will lead to many ecological problems like floods, droughts, soil erosion, loss of wildlife, and changes in climate. It disturbs the natural balance of the environment.
In simple words: Cutting down trees causes problems like floods, dry weather, soil loss, and animals losing their homes.

🎯 Exam Tip: When answering about environmental consequences, mention a range of impacts, not just one, to show a comprehensive understanding.

 

Question 2. What would happen if the habitat of wild animals is disturbed?
Answer: If the habitat of wild animals is disturbed, the biological diversity cannot be maintained, and it cannot promote economic activities that generate revenue for the government. Disturbing animal homes harms their ability to survive and reproduce.
In simple words: If animals' homes are disturbed, many different kinds of animals will be lost, and it will harm nature.

🎯 Exam Tip: Connect habitat disturbance to both environmental (biodiversity loss) and economic (revenue from eco-tourism) impacts.

 

Question 3. What are the agents of soil erosion?
Answer: The main agents of soil erosion are high-velocity wind, strong air currents, flowing water, landslides, and human activities like deforestation, farming, mining, and overgrazing by cattle. These factors all contribute to the breakdown and movement of soil.
In simple words: Strong wind, fast-moving water, landslides, cutting down trees, farming, mining, and too much grazing by animals all cause soil to wear away.

🎯 Exam Tip: Categorize the agents into natural forces (wind, water, landslides) and human activities to provide a complete answer.

 

Question 4. Why fossil fuels are to be conserved?
Answer: Fossil fuels like coal and petroleum are formed through a very slow process that takes a long period of time, meaning they are non-renewable. Therefore, they must be conserved for future generations to use. Their limited supply makes conservation crucial.
In simple words: Fossil fuels take millions of years to form and will run out, so we need to save them for people in the future.

🎯 Exam Tip: Emphasize the non-renewable nature and long formation period of fossil fuels as the primary reasons for their conservation.

 

Question 5. Solar energy is a renewable energy. How?
Answer: Solar energy is considered renewable because it is obtained directly from the sun, which is an inexhaustible source of energy. It is available in unlimited amounts in nature and can be harnessed continuously without depletion. The sun's energy constantly replenishes itself.
In simple words: Solar energy comes from the sun, and the sun's energy never runs out, so it can always be used again.

🎯 Exam Tip: The key characteristic of renewable energy is its continuous replenishment, and solar energy perfectly fits this definition.

 

Question 6. How are e-wastes generated?
Answer: E-wastes are generated from discarded, outdated, or non-repairable electrical and electronic devices. When old phones, computers, or TVs are thrown away, they become e-waste. This includes items like computers, mobile phones, and refrigerators.
In simple words: E-waste comes from old, broken, or unwanted electronics like phones and computers.

🎯 Exam Tip: Provide clear examples of common e-waste items to illustrate its definition.

VI. Short Answer Questions

 

Question 1. What is the importance of rainwater harvesting?
Answer: Rainwater harvesting is important for several reasons:
1. It helps to overcome the rapid depletion of groundwater levels.
2. It helps to meet the increasing demand for water.
3. It reduces floods and soil erosion by managing excess runoff.
4. Water stored in the ground through harvesting is less likely to be contaminated by human and animal wastes, making it safe for drinking and other purposes. This method efficiently uses a natural resource.
In simple words: Rainwater harvesting helps save groundwater, provides more water when needed, stops floods, and gives us clean water to drink.

🎯 Exam Tip: When listing points, ensure they are distinct and cover different benefits to showcase a broad understanding of the topic.

 

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

• It burns without smoke, which causes less pollution compared to other fuels.
• It is an excellent way to get rid of organic wastes like bio-waste and sewage material, turning waste into useful energy.
• The leftover slurry after biogas production is good manure, rich in nitrogen and phosphorus, helping plants grow.
• It is safe and convenient to use as a cooking fuel.
• It can reduce the number of greenhouse gases emitted into the atmosphere.

Biogas is a sustainable and eco-friendly energy source.
In simple words: Biogas is good because it burns cleanly with less pollution, helps get rid of organic waste, makes good plant food, is easy to use, and reduces bad gases in the air.

🎯 Exam Tip: When listing advantages, consider both the direct benefits (like clean fuel) and indirect environmental benefits (like waste management and reduced emissions).

 

Question 3. What are the environmental effect caused by sewage?
Answer: Sewage water causes agricultural contamination and environmental degradation, and it pollutes water resources. It introduces harmful bacteria and chemicals into water bodies, making them unsafe for living organisms. Untreated sewage can also spread diseases.
In simple words: Sewage water pollutes farms and nature, making water dirty and harmful.

🎯 Exam Tip: Focus on the two main types of environmental effects: contamination (of agriculture and water) and overall degradation.

 

Question 4. What are the consequences of deforestation?
Answer: The consequences of deforestation are far-reaching:

• Deforestation harms animals and damages the food chain, as many species lose their homes and food sources.
• It becomes a significant threat to the economy, quality of life, and the future of the environment by disrupting ecosystems.
• It leads to the loss of many forests, reducing biodiversity and natural resources.
• It gives rise to ecological problems such as floods, droughts, soil erosion, loss of wildlife, extinction of species, imbalance of biogeochemical cycles, changes in climatic conditions, and desertification.

Cutting down trees has many negative impacts on our planet.
In simple words: Deforestation hurts animals, the economy, and the environment. It causes floods, dry weather, soil loss, and makes animals disappear.

🎯 Exam Tip: When listing consequences, try to cover different aspects: impacts on wildlife, climate, soil, and human economy to show a comprehensive understanding.

 

Question 5. What are the consequences of soil erosion?
Answer: The effects of soil erosion include the loss of land fertility, humus, and vital nutrients, making it difficult for plants to grow. It also leads to increased pollution and sedimentation in streams and rivers, harming aquatic life. Degraded lands are less able to hold water, which can worsen flooding and reduce water availability for crops. The loss of topsoil is a significant environmental challenge.
In simple words: Soil erosion makes the land less fertile, pollutes rivers, and makes floods worse.

🎯 Exam Tip: Link soil erosion not just to land degradation but also to its impacts on water bodies and agricultural productivity.

 

Question 6. Why is the management of forest and wildlife resource considered as a challenging task?
Answer: The management of forest and wildlife resources is considered a challenging task for several reasons:

• Deforestation leads to a lack of oxygen, which affects all life forms.
• People sometimes kill animals to use their body parts for products, harming wildlife.
• There is often a lack of public awareness about the importance of conservation.
• Global warming and climate change put stress on ecosystems, making management harder.
• Water scarcity and changes in rainfall patterns negatively impact forests.
• People cut down trees for economic benefits, such as wood or land.
• Poaching (illegal hunting) directly reduces wildlife populations.
• Forests cannot be easily irrigated like farm fields and rely heavily on natural rain.
• Changes in rainfall patterns affect forest growth and can lead to their destruction.

These complex issues make conservation very difficult.
In simple words: Managing forests and wildlife is hard because people cut trees, kill animals, and often don't know why it's important. Also, climate change, water problems, and poaching make it even tougher.

🎯 Exam Tip: When discussing challenges, cover both human-induced problems (deforestation, poaching, lack of awareness) and natural environmental changes (climate change, rainfall patterns).

VIII. Assertion And Reasoning:

 

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.
In simple words: Both statements are correct, and the second statement clearly explains why the first statement is true. Collecting rainwater helps put water back into the ground.

🎯 Exam Tip: For assertion-reason questions, first check if both statements are individually true. Then, see if the reason directly explains the assertion by thinking "because" between them.

 

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: (c) Assertion is true but Reason is false.
In simple words: The first statement is true because CFL bulbs save electricity. The second statement is false because even if CFLs cost more at first, they save money in the long run by using less electricity.

🎯 Exam Tip: Evaluate both the assertion and the reason independently for truthfulness. Then, check if the reason correctly justifies the assertion, even if both are true.

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: We need to conserve coal and petroleum because their formation from biomass degradation is an extremely slow process, taking millions of years for renewal. Also, coal is heavily used for electricity generation, and petroleum powers automobiles, trucks, trains, ships, and airplanes. Since these fuels are consumed much faster than they can be naturally replenished, they are exhaustible resources that must be saved for the future. We must manage our use of them carefully.
In simple words: We must save coal and petroleum because they take a very, very long time to form again. We use them for electricity and vehicles, and they will run out if we don't conserve them.

🎯 Exam Tip: Highlight the contrast between the extremely slow formation rate of fossil fuels and their rapid consumption rate to explain the need for conservation.

 

Question 2. How can we make the best use of non-conventional energy resources from?
Answer: To make the best use of non-conventional energy resources, we should aim for quick replenishment, efficient storage, and wide-scale adoption. For example, solar and wind power can be harnessed through advanced technologies, and biomass can be processed for biogas production. It is important to invest in research for better efficiency. Hydrocarbons are formed over thousands of years when dead plants and animals are buried, which makes them different from non-conventional sources.
In simple words: We can use non-conventional energy best by finding ways to make them quickly available, storing them well, and using them widely in our daily lives.

🎯 Exam Tip: When discussing optimal use, think about methods that enhance availability, efficiency, and environmental benefits of these energy sources.

 

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: The Government is banning polythene bags and plastics because they are non-biodegradable materials that cause severe environmental pollution. They are harmful to both wildlife and marine life, often ending up in oceans and choking animals. Plastics are also very difficult to clean up and remove from the environment.
Alternatives to plastic bags include using jute bags, canvas bags, or paper bags, which are biodegradable and reusable.
This ban is likely to improve the environment by controlling pollution, making the surroundings cleaner, and creating a better place for all organisms to live. It encourages more sustainable practices.
In simple words: The government is banning plastic bags because they pollute a lot and hurt animals. We should use cloth or paper bags instead. This ban will make our environment cleaner and safer for everyone.

🎯 Exam Tip: Clearly state the reasons for the ban (non-biodegradability, harm to wildlife), provide practical alternatives, and explain the positive environmental impacts of the ban.

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: It is not currently possible to rely solely on solar cells to meet all our energy needs for these reasons:

• The installation cost of solar cell panels is very high because silicon wafers, used in the cells, are expensive, as is the silver used for connections.
• Solar cells produce direct current (DC) electricity. To operate most common alternating current (AC) devices, this DC power needs to be converted using an inverter, which adds to the cost and complexity.
• The efficiency of energy conversion in solar cells is relatively low compared to other methods of generating electricity, meaning a large area is needed to produce significant power.

While solar energy is clean, these challenges limit its full-scale adoption as the sole energy source.
In simple words: We can't use only solar cells for all our energy because they cost a lot to set up, they make a different kind of electricity that needs changing, and they don't turn much sunlight into power compared to other ways.

🎯 Exam Tip: When discussing limitations, focus on practical aspects such as cost, type of electricity produced, and efficiency, which are key challenges for widespread solar adoption.

IX. Higher Order Thinking Skills:

 

Question 1. Although coal and petroleum are produced by degradation of biomass, yet we need to conserve them. Why?
Answer: Coal and petroleum are formed very slowly over thousands of years from dead plants and animals. Because their formation takes such a long time, they are considered non-renewable resources, meaning they cannot be easily replaced once used up. Coal is mainly used to make electricity, and petroleum powers cars, trucks, trains, ships, and airplanes. Since these fuels are used quickly and take a very long time to renew, we must conserve them to prevent them from running out completely. It's like spending money faster than you earn it; eventually, you'll have none left.
In simple words: Coal and petroleum form very slowly over a long time from old living things. We use them quickly for electricity and vehicles. We need to save them because they will run out if we don't.

🎯 Exam Tip: When explaining conservation, emphasize the difference between how quickly we consume resources versus how slowly they are formed naturally.

 

Question 2. non-conventional energy resources from conventional energy resources?
Answer: Non-conventional energy sources are those that are constantly replenished and available naturally, like solar, wind, and tidal energy. Conventional energy sources are those that exist in limited quantities and take a very long time to form, such as coal and petroleum. Non-conventional sources are generally cleaner and cause less pollution compared to conventional sources. For instance, solar power does not release harmful gases, unlike burning coal.
In simple words: Non-conventional energy means sources that never run out, like sun and wind. Conventional energy means sources that can run out, like coal and oil.

🎯 Exam Tip: Remember to name specific examples for both types of energy resources to clearly show your understanding.

 

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: The Government is banning polythene bags and plastics because they are non-biodegradable, meaning they do not break down naturally in the environment. This causes severe environmental pollution, harming wildlife and marine life when ingested, and accumulating in landfills. They are also very hard to clean up and remove. Alternatives to plastic bags include jute bags, canvas bags, and paper bags, which are biodegradable or reusable. This ban is likely to improve the environment by reducing pollution on land and in water bodies, protecting animals from accidental ingestion of plastic, and encouraging the use of more sustainable materials. This helps create a cleaner, healthier place for all living organisms. This move helps reduce the amount of waste that stays in nature for hundreds of years.
In simple words: The government is banning plastic bags because they pollute the environment and harm animals, as they do not break down. We can use cloth or paper bags instead. This will make our Earth cleaner and safer for everyone.

🎯 Exam Tip: When discussing environmental bans, always mention the problem (non-biodegradable), specific harm (wildlife, pollution), and solutions (alternatives, benefits of the ban).

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: It is currently not fully possible to meet all our energy needs using only solar cells for several reasons:
• The cost to install solar cell panels is very high. This is because silicon wafers, used in solar cells, and the silver connecting them are expensive. This makes the initial setup costly for many.
• Solar cells produce Direct Current (D.C.) electricity. Most household appliances and large-scale grids use Alternating Current (A.C.). To convert D.C. to A.C., an inverter is needed, which adds another layer of cost and complexity.
• The efficiency of converting sunlight into electricity using solar cells is still relatively low compared to other methods of generating electricity. This means a larger area and more cells are needed to produce the same amount of power, making it less practical for very large energy demands. While solar technology is improving, these factors currently limit its universal application for all energy needs.
In simple words: We cannot use only solar cells for all our energy because they are expensive to set up, they make a different type of electricity (DC) that needs to be changed for most homes, and they don't turn sunlight into power very efficiently.

🎯 Exam Tip: Focus on the economic and technical challenges of solar energy as practical reasons why it can't meet all needs, despite being a clean source.

 

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 wastes like vegetable peels can be disposed of by composting. In composting, these biodegradable solid wastes are broken down by microbes or earthworms. They turn into humus, which is a rich soil-like material that can be used as fertilizer. This method protects the environment by turning waste into something useful and reducing landfill waste.
(b) Industrial wastes like metallic cans should be recycled. This involves melting the metallic ions from the cans into molten aluminum. Any coatings or inks on the aluminum are removed during this process. The purified aluminum is then used to make new products. Recycling protects the environment by saving natural resources, reducing energy use, and cutting down on pollution from making new metals. This process also means fewer cans end up in landfills, keeping our planet cleaner.
In simple words: Vegetable peels can be composted, where small living things turn them into good soil. Metallic cans can be melted down and used again to make new things. Both ways protect our Earth by making less waste and using fewer new materials.

🎯 Exam Tip: Clearly distinguish between composting for organic waste and recycling for inorganic waste, and explain how each method specifically helps the environment.

 

Question 3. List any three activities based on the 3R approach to conserve natural resources.
Answer: The 3R approach for conserving natural resources includes Reduce, Reuse, and Recycle.
• **Reduce:** This means lowering the amount of waste generated in the first place. For example, using a reusable water bottle instead of buying single-use plastic bottles reduces plastic waste.
• **Reuse:** This involves finding new purposes for items instead of throwing them away. An example is using old glass jars to store food or craft supplies instead of buying new containers.
• **Recycle:** This is about processing used materials to create new products. For instance, recycling old newspapers into new paper reduces the need to cut down more trees. These three activities together help manage solid waste and preserve our natural resources for a longer time.
In simple words: The 3R approach is Reduce, Reuse, Recycle. Reduce means making less waste, like using less packaging. Reuse means using things again, like refilling a bottle. Recycle means turning old things into new things, like making new paper from old paper.

🎯 Exam Tip: Always define each 'R' and provide a clear, simple example for each that illustrates its application in daily life.

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.
In simple words: The best way to throw away trash is to sort it first into things that rot naturally (biodegradable) and things that don't (non-biodegradable) before putting them in separate bins.

🎯 Exam Tip: Always choose the option that promotes sorting and responsible disposal, as it is key to effective waste management.

 

Question 2. The solar energy 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%
In simple words: A little less than 47% of the sun's energy that enters our atmosphere actually makes it all the way down to the Earth's surface.

🎯 Exam Tip: Numerical data questions require precise recall. Note down key percentages related to environmental science.

 

Question 3. Chipko Andolan is associated with
(a) Protesting against pasting of posters on walls.
(b) Saving money
(a) Saving trees.
Answer: (a) Saving trees.
In simple words: The Chipko Movement is famous for its efforts to protect and save trees.

🎯 Exam Tip: Connect movements with their core purpose. The Chipko Movement's name itself means "to hug," referring to people hugging trees to protect them.

 

Question 4. The technique to harness the water energy is _______
(a) hydropower
(b) electrical energy
(c) tidal energy
(d) hydraulic fracturing
Answer: (a) Hydropower
In simple words: Hydropower is the method used to capture energy from flowing water.

🎯 Exam Tip: Understand the specific terminology for different energy sources. Hydropower is the correct term for energy from moving water.

 

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 options
Answer: (d) All the options
In simple words: Saving wildlife means stopping animal hunting, building safe places like national parks for them, and making it illegal to buy or sell animals that are in danger of disappearing. All these actions are part of wildlife conservation.

🎯 Exam Tip: Wildlife conservation is a broad topic, so remember that it includes various strategies like legal protection, habitat preservation, and preventing illegal activities.

 

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
In simple words: Using windmills to create power for watering crops is an eco-friendly activity because it uses clean wind energy and doesn't pollute.

🎯 Exam Tip: Identify activities that use renewable resources and minimize pollution as eco-friendly. Avoid those that cause emissions or waste.

 

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
In simple words: From the given choices, wind, wood, and sun are the only group of energy sources that do not include any fossil fuels. They are all renewable or biomass-based.

🎯 Exam Tip: Know the examples of fossil fuels (coal, petroleum, natural gas) and non-fossil fuels (wind, solar, wood, hydro) to easily identify the correct combination.

 

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
In simple words: Planting many trees, which is called afforestation, helps groundwater levels stay high because trees allow more water to soak into the ground.

🎯 Exam Tip: Understand that afforestation increases infiltration, leading to higher groundwater levels. The other options lead to depletion.

 

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
In simple words: The incorrect statement is that forests do not conserve soil, because forests actually help protect soil from washing away or blowing away.

🎯 Exam Tip: Be careful with "wrong statement" questions. Identify the statement that is factually incorrect regarding the role of forests.

 

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.
In simple words: The main idea of the Chipko movement was to get local people involved and empower them to protect forests.

🎯 Exam Tip: The Chipko movement is a classic example of community-led conservation. Focus on the role of local people in its success.

II. Fill in the blanks:

 

Question 1. 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. mining
9. Hawaii
10. Kallanai
In simple words: This section fills in missing words about pollution, conservation movements, famous places, natural processes, and energy sources. It covers topics from vehicle pollution to historical dams and renewable energy.

🎯 Exam Tip: For fill-in-the-blanks, recall specific terms, names, and concepts related to environmental science and India's natural heritage. Review facts on pollution, conservation movements, and energy.

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.
In simple words: Both statements are correct: we should not destroy animal and plant homes (Assertion A), and this is because we need to save all living things (Reason R). Reason R explains why Assertion A is true.

🎯 Exam Tip: In assertion-reason questions, first check if both statements are individually true, then evaluate if the reason correctly explains the assertion.

 

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.
Answer: (b) Both Assertion and Reason are true but Reason is not the correct explanation of Assertion.
In simple words: The statement that just stopping hunting is not full wildlife conservation (Assertion) is true. The statement that some animals can overmultiply and run out of food (Reason) is also true. However, the reason does not explain why simply stopping hunting isn't "real" conservation; true conservation involves managing entire ecosystems, not just one factor.

🎯 Exam Tip: For complex assertion-reason questions, ensure the reason directly addresses *why* the assertion is true or false, not just states another true fact.

IV. Match the following:

 

Question 1. Match the following:

Answer:
A. (iii) Collect rain water in pond.
B. (i) e-Waste
C. (v) World wild life fund
D. (ii) Wild life photographer
E. (iv) One horned rhino
In simple words: This matching exercise connects different terms related to environmental management, such as water harvesting methods (Ooranai), types of waste (Cadmium), conservation organizations (WWF), environmental roles (Wild life photographer), and animal conservation initiatives (Indian Rhino vision 2020).

🎯 Exam Tip: For matching questions, identify keywords in each column and link them with their most relevant pair. Be precise with terms and their definitions.

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

 

Question 1. The devices used for harnessing sun energy is wind mill.
Answer: False – The devices used for harnessing sun energy are solar panels, not windmills. Windmills are used to harness wind energy. Solar panels convert sunlight directly into electricity or heat.
In simple words: This statement is false. Solar panels catch sun energy, while windmills catch wind energy.

🎯 Exam Tip: Clearly state "True" or "False" first. If false, provide the correct information or explanation to score full marks.

 

Question 2. Liquefied petroleum gas is obtained from petroleum.
Answer: True
In simple words: This statement is true; Liquefied Petroleum Gas (LPG) comes from petroleum.

🎯 Exam Tip: Basic facts about energy sources are often tested. Know the origins of common fuels like LPG.

 

Question 3. Harnessing the energy from flowing water to produce electricity is hydro power.
Answer: True
In simple words: This statement is true; getting electricity from moving water is called hydropower.

🎯 Exam Tip: Understand the definitions of different types of renewable energy. Hydropower specifically refers to energy from water flow.

 

Question 4. 12% of e-wastes are from computer components.
Answer: False – 12% of e-wastes are from telecommunication components. While computers contribute to e-waste, telecommunication devices are a significant source for this specific percentage.
In simple words: This statement is false. 12% of electronic waste comes from phone and communication parts, not just computer parts.

🎯 Exam Tip: Pay attention to specific statistics when they appear. Small differences in terms like "computer components" versus "telecommunication components" can change the answer.

 

Question 5. LED bulbs consume more electrical energy.
Answer: False – LED bulbs consume less electrical energy compared to traditional incandescent or CFL bulbs. They are known for their energy efficiency. This is why LED bulbs are recommended for saving electricity.
In simple words: This statement is false. LED bulbs actually use less electricity than older types of bulbs.

🎯 Exam Tip: Know the energy efficiency characteristics of common household items like LED bulbs, as this is a frequently tested concept in environmental studies.

VI. Answer in a word or sentence:

 

Question 1. Define Conservation.
Answer: Conservation is about properly using and managing nature and its resources. It ensures that these resources are available for a long time, preventing waste and harm. This includes protecting animals, plants, and natural spaces.
In simple words: Conservation means taking good care of nature and its resources so they last for the future.

🎯 Exam Tip: A good definition includes both the "what" (proper use and management) and the "why" (for future generations) of conservation.

 

Question 2. What are the ways to sustain our resources?
Answer: To sustain our resources, we need to use them continuously without depleting them. This involves practices like using energy efficiently, avoiding waste of water, minimizing the use of plastics, and handling non-biodegradable materials carefully. These actions ensure that natural resources remain available for a long time. For example, turning off lights when not needed is an efficient use of energy.
In simple words: To keep our resources lasting, we should use energy wisely, save water, use less plastic, and take care of non-biodegradable trash.

🎯 Exam Tip: Focus on practical, actionable steps for resource sustainability, such as efficient use, waste reduction, and careful management of non-recyclable materials.

 

Question 3. Suggest any two activities in daily life which are eco-friendly.
Answer: Two eco-friendly activities in daily life are:
1. Carrying jute or canvas bags for shopping instead of plastic bags. These bags are reusable and reduce plastic waste.
2. Switching off electrical and electronic devices when not in use. This saves electricity, which often comes from burning fossil fuels, thus reducing carbon emissions. These small changes help protect the environment in big ways.
In simple words: Two eco-friendly things we can do are using cloth bags for shopping and turning off lights and gadgets when we don't need them.

🎯 Exam Tip: Provide clear, simple, and distinct examples of eco-friendly actions that can be easily adopted in daily routines.

 

Question 4. Name four substances that can be recycled.
Answer: Four substances that can be recycled are newspapers, PET plastic bottles, steel cans, and glass containers. Recycling these materials helps conserve natural resources and reduces the amount of waste sent to landfills. For example, old newspapers can be turned into new paper products.
In simple words: Newspapers, plastic bottles, steel cans, and glass jars are four things that can be recycled and used again.

🎯 Exam Tip: List common, easily recognizable recyclable materials. Providing examples shows a practical understanding of recycling.

 

Question 5. List any two common methods by which solid wastes of urban areas are disposed off.
Answer: Two common methods for disposing of solid wastes in urban areas are:
1. **Segregation of waste:** This involves separating different types of waste materials, such as biodegradable (things that rot) and non-biodegradable (things that don't rot) wastes, before disposal.
2. **Sanitary landfill:** In this method, solid wastes are dumped into low-lying areas. The layers of waste are compacted by trucks, and then covered with soil to allow them to settle and decompose over time, especially organic matter. These methods aim to manage the large volume of waste generated in cities.
In simple words: Two ways cities get rid of trash are by separating it into types (like wet and dry waste) and by burying it in large, special areas called landfills.

🎯 Exam Tip: Focus on the primary, large-scale methods used for urban waste management. Segregation and landfills are fundamental practices.

 

Question 6. What is chipko movement?
Answer: The Chipko movement was a non-violent social and ecological movement. Its main goal was to protect and conserve trees. Villagers in the Chamoli district of Uttar Pradesh started this movement by hugging trees to prevent them from being cut down by loggers. This action showed their strong resolve to save their forests. The movement became a symbol of peaceful environmental protest.
In simple words: The Chipko movement was a peaceful protest where villagers hugged trees to stop them from being cut down, mostly in Uttar Pradesh.

🎯 Exam Tip: When describing historical movements, include its nature (non-violent), purpose (tree conservation), key action (hugging trees), and location for a complete answer.

 

Question 7. Give the reason for decline in wildlife population.
Answer: The main reasons for the decline in wildlife population are over-exploitation and the shrinking of forest cover areas. Over-exploitation includes excessive hunting (poaching) and trapping of animals. Shrinking forest cover means less habitat available for animals, leading to loss of food and shelter. These factors directly contribute to animals facing extinction. When their homes are destroyed, animals struggle to survive.
In simple words: Wildlife numbers are going down because humans use too many resources from nature and their forest homes are getting smaller.

🎯 Exam Tip: Identify the two major drivers of wildlife decline: direct human impact (over-exploitation) and habitat loss (shrinking forest cover).

VII. Short Answer Questions:

 

Question 1. What is conservation? Why should we conserve natural resources?
Answer: Conservation is the proper utilization and management of nature and its resources. We should conserve natural resources because it is vital to preserve them for future generations. If we use them up carelessly, there won't be enough for people who come after us. By conserving resources, we help build a sustainable world that can last forever, ensuring that essential things like clean water and air are available for everyone. This responsible management also protects the balance of ecosystems.
In simple words: Conservation means using nature and its resources wisely. We must conserve them so that there is enough for people in the future and to keep our planet healthy forever.

🎯 Exam Tip: Always link the definition of conservation to its purpose, which is ensuring resource availability and sustainability for the long term.

 

Question 2. How can you as an individual contribute to the management of coal and petroleum.
Answer: As an individual, you can contribute to managing coal and petroleum resources in several ways:
1. Minimize the use of coal and petroleum as energy sources. This means turning off lights, using fewer electronic devices, and choosing energy-efficient appliances.
2. Use cleaner fuels like Compressed Natural Gas (CNG) or Liquefied Petroleum Gas (LPG) in vehicles instead of petrol or diesel, if possible.
3. Rely more on renewable energy sources such as solar power, hydropower, wind energy, and tidal energy in your daily life. For example, installing a solar water heater helps reduce reliance on traditional fuels. By making these choices, you help reduce the demand for these limited fossil fuels.
In simple words: You can help save coal and petroleum by using less electricity, driving less or using bikes, and supporting energy from the sun or wind instead.

🎯 Exam Tip: Provide actionable advice for individuals, categorized by reducing consumption, switching to alternative fuels, and adopting renewable energy, to show a comprehensive understanding.

 

Question 3. What are the methods to conserve the forest?
Answer: To conserve forests, several methods can be adopted:
• **Afforestation:** This involves planting and protecting new trees to create or restore green cover. It directly helps in rebuilding forests, and destruction of existing trees should be avoided.
• **Social forestry programme:** This encourages active participation from the public in growing trees on common land. The aim is to produce firewood, fodder (animal feed), and timber for the benefit of local communities, reducing pressure on natural forests.
• **Forest Conservation through Laws:** Governments adopt strict laws and policies, such as the National Forest Policy, to conserve and protect forest areas. These laws prevent illegal logging and encroachment. These strategies work together to maintain forest health and size, which are crucial for the environment.
In simple words: We can save forests by planting more trees, getting communities to grow trees on shared land, and by having strict laws to protect forests.

🎯 Exam Tip: Categorize conservation methods into planting new trees, community involvement, and legal protection for a structured and complete answer.

 

Question 4. List the wild life conservation Initiatives in India.
Answer: India has launched several important wildlife conservation initiatives to protect its diverse fauna:
1. **Project Tiger:** Launched in 1973, this initiative aims to protect tigers and their habitats across India.
2. **Project Elephant:** Started in 1992, this project focuses on conserving elephants, their habitats, and migration corridors.
3. **Crocodile Conservation Project:** This initiative was launched in 1976 to protect different species of crocodiles found in India.
4. **Sea Turtle Conservation Project:** Initiated in 1999, this project works to protect sea turtles and their nesting sites along India's coasts.
5. **Indian Rhino Vision 2020:** This program aims to conserve at least 3000 greater one-horned rhinos in Assam, India by 2020. These projects have been crucial in bringing back several endangered species and preserving biodiversity.
In simple words: India has many programs to save animals, like Project Tiger (for tigers), Project Elephant (for elephants), Crocodile Conservation, Sea Turtle Conservation, and Indian Rhino Vision 2020 (for rhinos).

🎯 Exam Tip: List key conservation projects by name and their associated animals, along with the launch year if possible, to demonstrate detailed knowledge.

 

Question 5. What are the steps to be taken to conserve coal and petroleum resources?
Answer: To conserve coal and petroleum resources, several steps can be taken:
• Saving electricity will indirectly reduce the use of coal, as much of our electricity is generated from coal-fired power plants. Turn off lights and fans when not needed.
• Using bicycles for short distances instead of cars, scooters, or motorcycles significantly reduces petroleum consumption. This also promotes a healthy lifestyle.
• Using pressure cookers can reduce the consumption of kerosene and LPG during cooking, as they cook food faster with less fuel.
• Solar cookers and solar heaters should be used wherever possible, as they harness renewable solar energy, reducing the need for fossil fuels.
• Motor vehicles should be designed to be fuel-efficient. This means they should use less fuel to cover the same distance, which also helps reduce air pollution. These measures collectively reduce our reliance on these finite resources.
In simple words: To save coal and petroleum, we should save electricity, use bicycles for short trips, cook with pressure cookers, use solar appliances, and choose cars that use less fuel.

🎯 Exam Tip: Focus on actions that reduce demand for these fuels, either directly (less driving, efficient cooking) or indirectly (saving electricity, using solar alternatives).

 

Question 6. What are the advantages of solar energy?
Answer: Solar energy offers several important advantages:
1. It is widely available across many parts of our country, especially India, and is free of cost once the initial equipment is installed. The sun provides a continuous supply of energy.
2. Solar energy is a renewable source, meaning it will not run out during our lifetime, unlike fossil fuels.
3. It can be used for various purposes, such as generating electricity (solar panels) or heat (solar water heaters and cookers).
4. It does not cause pollution. Solar power generation produces no greenhouse gas emissions or other harmful pollutants during operation. These benefits make solar energy a promising solution for future energy needs.
In simple words: Solar energy is good because it is free, never runs out, can make electricity or heat, and does not pollute the air.

🎯 Exam Tip: When listing advantages, cover economic (free), environmental (renewable, no pollution), and practical (versatile uses) aspects of solar energy.

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 aims of wildlife conservation are:
• To control and limit the over-exploitation of different animal and plant species.
• To preserve plants and animals, preventing their extinction.
• To maintain threatened species and protect those on the verge of disappearing forever.
• To preserve endangered species specifically.
• To study the natural relationships between plants and animals in their habitats.
• To prohibit hunting and poaching of wild animals.
• To establish national parks, wildlife sanctuaries, and protected areas known as biosphere reserves. These aims ensure a balanced ecosystem for all living things.
(b) The provisions of the Wildlife Protection Act include:
• Prohibiting the killing and hunting of specific animals listed in the act.
• Establishing sanctuaries, national parks, and closed areas to provide safe habitats for wildlife conservation.
• Creating special schemes for the preservation of endangered species, offering them focused protection.
• Establishing a central zoo authority and recognizing zoos for conservation and breeding programs.
• Restricting, regulating, or prohibiting trade in wild animals and products obtained from them to prevent illegal wildlife trade. This act provides a legal framework to safeguard India's rich biodiversity.
In simple words: (a) Wildlife management aims to stop too much hunting, save plants and animals from extinction, protect their homes, and create safe parks for them. (b) The Wildlife Protection Act stops animal killing, sets up wildlife safe zones, helps save rare animals, and controls trade in animal parts.

🎯 Exam Tip: For multi-part questions, ensure both parts are addressed thoroughly. For wildlife management, cover protection, habitat, and legal aspects. For the Act, list its key regulatory and protective measures.

 

Question 2. Give the various steps to conserve non-renewable resource.
Answer: Non-renewable resources like coal and petroleum are limited and take millions of years to form, so conserving them is crucial. Here are several steps for their conservation:
1. **Minimize consumption:** Reduce the overall use of these resources. For example, turn off lights and electronic devices when not in use to save electricity, which often comes from coal.
2. **Use efficiently:** Implement technologies and practices that get more out of less resource. For instance, using fuel-efficient vehicles consumes less petrol.
3. **Switch to alternatives:** Promote and adopt renewable energy sources like solar, wind, and hydro power. Using solar water heaters instead of electric geys reduces reliance on traditional energy.
4. **Recycle and reuse:** For materials like metals (often extracted with non-renewable energy), recycling reduces the need for new extraction. For example, recycling aluminum cans saves a lot of energy.
5. **Public awareness:** Educate people about the importance of conservation and how their daily actions impact resource availability. By following these steps, we can slow down the depletion of these vital resources.
In simple words: To save resources that cannot be easily replaced, we need to use less of them, use them wisely, switch to renewable energy like solar power, recycle items, and teach everyone why it's important to conserve.

🎯 Exam Tip: Structure your answer with clear points, starting with reduction and moving to alternatives and responsible consumption, to cover all aspects of non-renewable resource conservation.

 

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 also called photovoltaic devices. They are made from silicon and turn sunlight directly into electricity. These cells produce electricity without causing any pollution. They do not release harmful gases, nor do they involve burning anything or producing waste. Solar cells are very useful for powering various small devices and systems.

• They can be used for street lighting, traffic signals, water pumping, and battery charging systems.
• They are used in artificial satellites and space probes for space missions.
• They help in radio and TV transmission to distant areas.
• They are also found in calculators, electronic toys, and watches.

(b) Solar panel: A solar panel is formed when many solar cells are connected side by side. This arrangement increases the capacity to provide more electric current. However, making these panels is quite an expensive process.

(c) Solar cooker: A solar cooker is usually an insulated metal or wooden box. It is painted black inside to absorb as much sunlight as possible. A thick glass sheet covers the top of the box. A reflector, often a mirror, is attached to the box. This mirror helps to direct more sunlight into the cooker. The food inside is cooked by the heat energy from the sun's rays.

(d) Solar thermal power plant: In these plants, many solar panels are used to focus and collect sun rays. This heat is then used to warm water and turn it into steam. The steam then drives turbines to make electricity. Solar energy is free and widely available in our country. It does not cause any pollution and is considered a renewable source of energy.
In simple words: Solar cells turn sunlight into electricity. Many cells together form a solar panel. A solar cooker uses the sun's heat to cook food. Solar thermal power plants use the sun's heat to make steam, which then makes electricity. All these methods use the sun, which is a clean and free energy source.

🎯 Exam Tip: When writing about different solar technologies, focus on their basic principle, how they work, and their main applications and benefits.

 

Question 4. Explain the tidal energy with its advantages.
Answer: Tidal energy comes from the natural movement of ocean water caused by tides. Tides are the regular rise and fall of sea levels, which happen because of the gravitational pull from the Moon and the Sun on Earth's oceans. This constant motion provides a powerful, predictable source of energy.
A tidal stream is a fast-moving body of water created by these tides. Turbines are placed in these tidal streams. When the strong tidal currents hit the turbine blades, they rotate, and this movement is converted into electric energy.
Advantages of tidal energy:
1. Tidal energy does not cause any pollution. It is a clean source of power.
2. It does not use any fuel and produces no waste materials.
3. Tides are very predictable, so electricity can be generated reliably at specific times.
4. Water is heavier and denser than air, which means it can generate electricity more efficiently at lower speeds compared to wind turbines.
In simple words: Tidal energy uses the power of rising and falling ocean tides to make electricity. It is clean, uses no fuel, is predictable, and works well because water is heavy.

🎯 Exam Tip: When discussing tidal energy, remember to explain *what* tides are and *how* their movement is converted into electricity, along with its key benefits like predictability and being pollution-free.

 

Question 5. Explain the convention method of waste water treatments.
Answer: Traditional ways of treating wastewater involve several steps. These steps clean the water that comes from homes and factories so it can be reused safely.
The common methods include:
(a) Pre-screening: This is the first step. Wastewater from homes and industries is passed through screens. These screens catch larger solid things like plastic, rags, and other debris, removing them from the water.
(b) Aeration: After pre-screening, the wastewater is pumped into a large tank called an aeration tank. In this tank, air is mixed into the water. This helps tiny living organisms (microbes) to grow and break down harmful substances in the water. This biological cleaning happens due to the presence of air.
Sedimentation process: During aeration, the solid bits in the water settle down to the bottom. This settled material is called sludge. The water above it becomes clearer.
(c) Sludge removal: The sludge, which contains the waste material, is regularly taken out of the tank. This sludge is then sent for safe disposal, as it contains concentrated pollutants.
Disinfection: After removing sludge, the treated water still needs further cleaning. It is disinfected using chemicals like chlorine or by exposing it to ultraviolet (UV) light. This step kills any remaining germs and makes the water safe.
(d) Water recycling: Finally, the cleaned water can be used again. It can be supplied for domestic uses like washing or industrial purposes, helping to save fresh water resources.
In simple words: Wastewater treatment cleans dirty water using steps like screening out big pieces, bubbling air to let microbes eat dirt, letting solids settle into sludge, killing germs, and then reusing the water.

🎯 Exam Tip: Remember the main stages of wastewater treatment: physical screening, biological breakdown (aeration), sludge management, and disinfection. Each stage plays a crucial role in purifying water.

IX. Hot Questions:

 

Question 1. Name the movement aimed at the protection and conservation of trees. In which district was it originated?
Answer: The movement aimed at protecting and conserving trees is the Chipko movement. This movement started in the Chamoli district of Uttarakhand. It highlighted how local communities can play a crucial role in environmental conservation.
In simple words: The Chipko movement helps protect trees and began in the Chamoli district of Uttarakhand.

🎯 Exam Tip: When asked about environmental movements, always include the name of the movement and its key location or origin.

 

Question 2. Name any two wildlife conservation initiatives in India.
Answer: Two important wildlife conservation initiatives in India are the Project Tiger and the Project Elephant. These projects were launched to protect specific endangered animal species and their habitats, showing India's commitment to biodiversity.
In simple words: Project Tiger and Project Elephant are two ways India is trying to save wild animals.

🎯 Exam Tip: Remember to list specific projects when asked for conservation initiatives, as they represent concrete government efforts.

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) When natural resources are used too much, they start to run out. This leads to an energy crisis, meaning there isn't enough energy for everyone. It also disturbs the natural balance of the environment, causing harm to ecosystems and possibly making life difficult for living things. For instance, too much logging leads to deforestation, impacting rainfall patterns.
(b) To stop this decline, we can use renewable energy sources like solar power and wind energy more often. These sources do not run out and cause less harm to the environment. Also, we must use existing resources carefully and avoid wasting them.
In simple words: Using too many natural resources causes energy shortages and harms nature. We can stop this by using green energy and being careful with what we have.

🎯 Exam Tip: When explaining the effects of resource depletion, always mention both the direct impact (e.g., energy crisis) and the broader environmental consequences (e.g., ecological imbalance). For prevention, focus on renewable energy and sustainable practices.