SEBA Class 10 Science Chapter 14 – Sources of Energy Solutions & Summary
Searching for reliable solutions for Class 10 Science Chapter 14 – “Sources of Energy”? Ospin Academy provides complete NCERT solutions for SEBA Assam students.
📖 Chapter Overview:
This chapter discusses different sources of energy, their classification into renewable and non-renewable resources, and the environmental impact of using these energy sources.
📌 Key Topics Covered:
- Conventional Sources of Energy (Fossil Fuels, Thermal Power Plants)
- Non-Conventional Sources of Energy (Solar, Wind, Hydropower)
- Nuclear Energy and Biomass Energy
- Environmental Consequences of Energy Usage
- Advantages and Disadvantages of Different Energy Sources
📌 Important Questions for Exams:
- What are conventional and non-conventional sources of energy? Give examples.
- Explain the working principle of a thermal power plant.
- Describe the advantages and limitations of solar energy.
- How does energy generation affect the environment?
- What is nuclear energy? Explain its advantages and risks.
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- Step-by-Step NCERT Solutions for SEBA Syllabus
- Conceptual Clarity with Detailed Explanations
- Chapter Notes for Quick Revision
- Interactive Diagrams and Real-Life Examples
Access the best solutions for SEBA Class 10 Science Chapter 14 – “Sources of Energy” only on Ospin Academy!
Class 10 Science (English Medium) PDF Solutions 2025-26 | SEBA Assam
Download Class 10 Science (English Medium) PDF with detailed solutions, MCQs, and extra practice questions for SEBA Assam 2025-26.
Textual Questions and Answers:
Page – 243
1. What is a good source of energy?
Answer: A good source of energy is one that:
1. Generates significant heat per unit mass.
2. Provides a large amount of work per unit mass.
3. Is readily available.
4. Can be easily stored and transported.
5. Is cost-effective.
6. Produces minimal smoke or pollution..
2. What is a good fuel?
Answer: A good fuel:
1. Is easily available in nature.
2. Has a high calorific value, providing more energy per unit mass.
3. Burns efficiently without leaving residues.
4. Produces little to no smoke and is environmentally friendly.
5. Is economical and affordable.
6. Burns at a controllable and steady rate.
3. If you could use any source of energy for cooking your food, which one would you use and why?
Answer: We would prefer to use L.P.G. or Gobar gas. Because these gases have high calorific value, not produce pollution, easily available and is economical.
Page – 248
1. What are disadvantages of fossil fuels?
Answer:
Disadvantages of fossil fuels are:
1. Air pollution.
2. The oxides of carbon, nitrogen, and sulphur that are released on burning fossil fuels are acidic oxides. These lead to acid rain which affects our water and soil resources
3. Global warming- the greenhouse effect of gases like carbon dioxide.
4. The fossil fuels are non-renewable sources of energy.
2. Why are we looking at alternative sources of energy?
Answer: The main reason why we are searching for an alternate source of energy is because fossil fuels are non-renewable sources of energy which means they are not available in abundant quantities and cannot be replenished. Fossil fuels will continue to get exhausted if their consumption is not controlled. Therefore, it is far better to switch to alternate sources of energy in order to apply the concept of sustainable development.
Geothermal energy is the energy which is obtained from the earth. This energy can be obtained from the hot spots that are formed when the molten rocks present at the core of the earth are pushed towards the earth9s crust. Hot springs are commonly used for the production of electricity in the geothermal power plants.
3. How has the traditional use of wind and water energy been modified for our convenience?
Answer: Earlier, the windmills were used to harness wind energy to do mechanical work such as lifting/drawing water from a well. Today, windmills are used to generate electricity.In windmills, the kinetic energy of wind is harnessed and converted into electricity.
Water energy which was used for transportation before is now a good source to generate electricity. Dams has been constructed on river for generating electricity.
Waterfalls were used as a source of potential energy which was converted to electricity with the help of turbines.
Page – 253
1. What kind of mirror-concave, convex or plane mirror would be best suited for use in a solar cooker? Why?
Answer: A concave mirror reflector would be best suited for use in a solar cooker. This is because a concave mirror is a converging mirror which converges all the light falling on it. It converges a large amount of sun’s heat rays onto the required area of cooking holder. A plane mirror does not converge all the light therefore, concave is used. And convex mirror reflector is a diverging mirror so it is also not used.
2. What are the limitations of the energy that can be obtained from the oceans?
Answer: The following are some of the limitations of ocean energy:
1. The tidal energy is affected by the relative positions of the earth, the sun, and the moon.
2. High dams are required for converting tidal energy into power.
3. Strong waves are necessary to generate electricity from wave energy.
4. A temperature difference of more than 20°C between hot surface water and cool water at depth is required to store ocean thermal energy.
3. What is geothermal energy?
Answer: Geothermal energy is the heat generated within the Earth. The term “Geo” means Earth, and “thermal” means heat in Greek. It is a renewable resource that can be harnessed for human use.
This heat originates from deep inside the Earth’s core, located about 2,900 kilometers (1,800 miles) beneath the Earth’s crust, making it the hottest part of our planet.
4. What are the advantages of nuclear energy?
Answer: Nuclear energy is preferred to fossil energy, hydro energy, thermal energy etc for the following reasons.
- One of the most low-carbon energy sources.
- It also has one of the smallest carbon footprints.
- It’s one of the answers to the energy gap.
- It’s essential to our response to climate change and greenhouse gas emissions.
- Reliable and cost-effective.
Page – 253
1. Can any source of energy be pollution free? Why or why not?
Answer: No source of energy can be called pollution-free, because, the use of any source of energy disturbs the environment in one way or the other. A source of energy like a solar cell is pollution free in actual operation but the assembly of the device might have caused some damage to the environment. So, in absolute sense, no source of energy can be called pollution free.
2. Hydrogen has been used as a rocket fuel. Would you consider it a cleaner fuel than CNG? Why or why not?
Answer: Hydrogen is a cleaner fuel than CNG. This is because the burning of hydrogen produces only water, which is totally harmless. On the Other hand, burning of CNG produces carbon dioxide gas and heating of the environment in the long run.
Some of the environment consequence of the increasing demand for energy are the following:
1. The combustion of fossil is producing acid rain and damaging plants (crops), soil and aquatic life.
2. The burning of fossil is increasing the amount of greenhouse gas carbon dioxide in the atmosphere.
3. The cutting down of trees from the forest (deforestation) for obtaining fir-wood is causing soil erosion and destroying wild life.
4. The construction of the hydro-power plants is disturbing ecological balance.
5. Nuclear power plants are increasing radioactivity in the environment.
The various factors which we should keep in mind while choosing a sources of energy are:
- The ease of extracting energy from that source
- The cost of extracting energy from the sources
- The efficiency of technology available to extract energy from that sources.
- The damage to environment which will be caused by using that sources.
Page – 254
1. Name two energy sources that you would consider to be renewable. Give reasons for your choices.
Answer: Hydro-Energy and Biomass energy are the renewable sources of energy:
1. Hydro-Energy is the energy produced by fast flowing water. It is a renewable source of energy because it is supplied by the water cycle in nature and it will never get exhausted.
2. The energy derived from flowing water, wind, sun and ocean are renewable sources because these sources can be harmless into energy so long as the present solar system exists.
2. Give the names of two energy sources that you would consider to be exhaustible. Give reasons for your choice.
Answer: Two exhaustible energy sources are as follows:
1. Coal: It is produced from dead remains of plants and animals that remain buried under the earth9s crust for millions of years. It takes millions of years to produce coal. Industrialization has increased the demand of coal. However, coal cannot replenish within a short period of time. Hence, it is a non-renewable or exhaustible source of energy.
2. Wood: It is obtained from forests. Deforestation at a faster rate has caused a reduction in the number of forests on the Earth. It takes hundreds of years to grow a forest. If deforestation is continued at this rate, then there would be no wood left on the Earth. Hence, wood is an exhaustible source of energy.
EXERCISES
1. A solar water heater can not be used to get hot water
(a) A sunny day.
(b) A cloudy day.
(c) A hot day.
(d) A windy day.
Answer: (b) A cloudy day.
2. In Which of the following is not an example of a biomass energy source?
(a) Wood.
(b) Gobar-gas.
(c) Nuclear energy.
(d) Coal.
Answer: (c) Nuclear energy.
3. Most of the sources of energy we use represent stored solar energy. Which of the following is not ultimately derived from the Sun’s energy?
(a) Geothermal energy.
(b) Wind energy.
(c) Nuclear energy.
(d) Biomass.
Ans: (c) Nuclear energy.
4. Compare and contrast fossil fuels and the Sun as direct sources of energy.
Ans: Similarity:
(a) Both are natural sources of energy.
(b) Both are widely used sources of energy.
Contrast:
(a) Fossil fuels are non-renewable. But the energy of Sun in renewable.
(b) Fossil fuels causes lot of air pollution. But the energy of Sun pollution free.
5. Compare and contrast biomass and hydro electricity as sources of energy.
Answer:
1. Biomass is a renewable source of energy and hydroelectricity is also a renewable source of energy.
2. The use of biomass by burning causes air pollution but the use of hydroelectricity does not cause any pollution.
3. Biomass energy can be obtained without using any special device but hydroelectricity can be produced only by establishing hydro-power plants.
6. What ar the limitations of extracting energy from
(a) The wind?
Answer: Limitations of wind energy:
(i) Need a large open space to couple a number of wind mills.
(ii) It is not available everywhere and at all the times.
(iii) Wind velocity must be sufficient.
(b) Waves?
Ans: Limitations of extracting energy from waves:
(i) Wave energy is viable proposition only when and where the waves are very strong. This has constraints of time and location.
(c) Tides?
Answer: Limitation of tidal energy:
(i) Its cost is huge and is not possible to build such dams everywhere.
(ii) Huge amount of silt gets deposited on basins in the dams.
7. On what basis would you classify energy sources as:
(a) Renewable and non-renewable?
Answer: The energy sources that can be regenerated are called renewable sources of energy.
Renewable energy:
1. A renewable source of energy is one that replaces itself in the natural world.
2. They include the sun, wind, water that is moving, biomass, etc.
3. The energy is derived from resources that can be regenerated naturally over time and are therefore considered to be renewable.
4. Despite the fact that the majority of renewable energy sources are sustainable, some are not.
Non-renewable energy:
1. Non-renewable energy sources are those that will run out of energy after a few hundred years.
2. The sources of energy that are non-renewable include coal, petroleum, etc.
3. The majority of the world’s energy comes from non-renewable resources like coal and oil, which are used to run companies, houses, and automobiles.
4. Renewable resources can naturally regenerate themselves, whereas nonrenewable resources cannot, which is how these two types of resources vary from one another.
(b) Exhaustible and inexhaustible?
Ans: Exhaustible sources are those energy sources which deplete and exhaust after a few hundred years.
8. What are the qualities of an ideal sources of energy?
Answer: Am ideal source of energy:
(i) Which would do a large amount of work per unit volume or mass.
(ii) Be easily accessible.
(iii) Be easy to store and transport and
(iv) Perhaps most importantly be economical.
9. What are the advantages and disadvantages of using a solar cooker? Are there places where solar cookers would have limited utility?
Answer:
Solar cookers use solar energy, a renewable and abundant energy source, to cook food.
Advantages:
1. Solar energy is free, making the operating cost of a solar cooker extremely low.
2. It is eco-friendly and does not produce any pollution.
3. It preserves nutrients in food as it cooks at moderate temperatures.
Disadvantages:
1. The initial manufacturing cost of a solar cooker is relatively high.
2. It depends on sunlight, so it cannot be used at night or on cloudy days.
3. Cooking with a solar cooker is slower compared to traditional methods.
Limited Utility:
Solar cookers are less effective in regions with limited sunlight, such as areas with short days, dense cloud cover, or high latitude locations.
10. What are the environmental consequences of the increasing demand for energy? What steps suggest to reduce energy consumption?
Answer: The ever-growing demand for energy has significant environmental consequences, as the exploitation of energy sources often disrupts ecological balance.
For instance, extracting and burning fossil fuels like coal, oil, and natural gas to meet energy needs releases large amounts of greenhouse gases, such as carbon dioxide and methane, contributing to global warming and air pollution. These emissions also harm human health and degrade ecosystems. Similarly, generating hydroelectric power through dam construction floods large areas of land, destroying habitats and displacing wildlife and humans. The submerged vegetation rots under anaerobic conditions, releasing methane, a potent greenhouse gas. Additionally, excessive mining for energy resources depletes natural landscapes and harms biodiversity.
Steps to Reduce Energy Consumption:
1. Judicious Use of Fossil Fuels: Fossil fuels should be used sparingly and efficiently to maximize their benefits while minimizing their harmful effects.
2. Adoption of Energy-Efficient Devices: Using energy-saving appliances such as LED bulbs, energy-efficient fans, and pressure cookers can significantly reduce energy wastage.
3. Regular Maintenance of Equipment: Machines and devices used for energy conversion must be maintained regularly to ensure they operate at maximum efficiency and consume less energy.
4. Promotion of Renewable Energy: Transitioning to renewable energy sources like solar, wind, and hydroelectric power can reduce dependency on fossil fuels and lower pollution levels.
5. Conservation Practices: Simple measures such as switching off lights, fans, and electronic devices when not in use, using public transport, and carpooling can reduce energy consumption significantly.
6. Awareness and Education: Educating individuals and communities about the importance of energy conservation and its environmental benefits can foster responsible energy use.
By adopting these measures, we can mitigate the environmental consequences of increasing energy demand while ensuring sustainable use of resources for future generations.
SEBA Class 10 Science Chapter 14 – Sources of Energy FAQs
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