Are you looking for NCERT Solutions for Class 10 Science Chapter 14 – Sources of Energy? If yes, you are in the right place! This chapter is one of the most important topics in Class 10 Science as it explains different sources of energy like fossil fuels, solar energy, wind energy, hydro power, biomass, and nuclear energy. Understanding this chapter not only helps you score well in exams but also builds awareness about renewable and non-renewable sources of energy that impact our daily life and future.
In this webpage, we provide detailed NCERT Solutions for Class 10 Science Chapter 14 (Sources of Energy) with easy explanations, step-by-step answers, and important points that will help you revise quickly and write accurate answers in the board exam. These solutions are prepared as per the latest NCERT guidelines and are useful for CBSE Class 10 students and competitive exam aspirants.
About Chapter 14 – Sources of Energy (Quick Summary):
Chapter 14 of Class 10 Science, Sources of Energy, focuses on the different ways we obtain energy for our daily needs. It explains the importance of energy in human life, limitations of fossil fuels, and the need for renewable sources of energy. The chapter covers solar energy, wind energy, water energy, biomass, geothermal energy, and nuclear energy along with their advantages and disadvantages. It also highlights the environmental consequences of using conventional energy sources and the importance of sustainable development.
NCERT Solutions for Class 10 Science Chapter 14 Intext Questions
Page Number: 243
Q1. What is a good source of energy?
Ans: A good source of energy is one that is easily available, gives a lot of energy, is cheap, safe to use, easy to store and transport, and does not harm the environment.
Q2. What is a good fuel?
Ans: A good fuel is one that produces a large amount of heat per unit mass, is cheap, easily available, easy to store and transport, and does not cause pollution or harm while burning.
Q3. if you could use any source of energy for heating your food, which one should you use and why?
Ans: I would use LPG because it is clean, easily available, produces high heat, and is convenient to use.
Page Number: 248
Q1. What are the disadvantages of fossil fuels?
Ans: Disadvantages of fossil fuels:
- They cause air pollution by releasing smoke and harmful gases.
- They release carbon dioxide, leading to global warming.
- They are non-renewable and will get exhausted soon.
- Their extraction and use can harm the environment and health.
Q2. Why are we looking at alternate sources of energy?
Ans: We are looking at alternate sources of energy because fossil fuels are limited, cause pollution, and lead to global warming. Alternate sources like solar, wind, and hydro energy are renewable, cleaner, and sustainable for the future.
Q3. How has the traditional use of wind and water energy been modified for convenience?
Ans: Wind energy is now used in windmills to generate electricity, and water energy is used in hydroelectric power plants.
Page Number: 253
Q1. What kind of mirror-concave, convex or plane – would be the best suited for use in a solar cooker? Why?
Ans: A concave mirror is best suited for a solar cooker because it converges the sunlight to a single point, producing high heat that helps in cooking food.
Q2. What are the limitations of the energy that can be obtained from the oceans?
Ans: Limitations of ocean energy:
- It requires high initial cost to set up power plants.
- It is location specific, only possible in coastal areas.
- The energy supply is not constant, depends on tides and waves.
- Technology is still complex and less developed.
Q3. What is geothermal energy?
Ans: Geothermal energy is the heat energy obtained from the inside of the Earth. It comes from hot rocks, magma, or underground hot water and steam, which can be used to produce electricity or for heating purposes.
Q4. What are the advantages of nuclear energy?
Ans: Advantages of nuclear energy:
- A small amount of fuel produces a very large amount of energy.
- It does not produce smoke or carbon dioxide, so less air pollution.
- It can provide a continuous supply of energy.
- It reduces dependence on fossil fuels.
Page Number: 253
Q1. Can any source of energy be pollution free? Why or why not?
Ans: No source of energy can be completely pollution free. Even renewable sources like solar, wind, or hydro cause some pollution during manufacturing, installation, or maintenance of devices. However, they cause much less pollution compared to fossil fuels.
Q2. Hydrogen has been used as rocket fuel. Would you consider it a cleaner fuel than CNG? Why or why not?
Ans: Yes, hydrogen is a cleaner fuel than CNG because its only by-product after burning is water, while CNG produces carbon dioxide, which causes pollution and global warming.
Page Number: 254
Q1. Name two energy sources that you would consider to be renewable. Give reasons for your choices.
Ans: Two renewable energy sources:
- Solar energy – It comes from the Sun, which is inexhaustible and available every day.
- Wind energy – It is generated from moving air, which is naturally replenished and never runs out.
Q2. Give the names of two energy sources that you would consider to be exhaustible. Give reasons for your choices.
Ans: Two exhaustible energy sources:
- Coal – It is formed over millions of years and will get depleted with continuous use.
- Petroleum – Its reserves are limited and cannot be replaced once exhausted.
Exercise Questions:
Q1. A solar water heater cannot be used to get hot
water on
(a) a sunny day
(b) a cloudy day
(c) a hot day
(d) a windy day
Answer:
(b) A cloudy day.
Q2. 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.
Q3. 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
Answer:
(a) Geothermal energy.
Q4. Compare and contrast fossil fuels and the sun as direct sources of energy.
Ans:
|
Point of Comparison |
Fossil Fuels |
Sun (Solar Energy) |
|
Availability |
Limited and exhaustible |
Inexhaustible |
|
Pollution |
Causes air pollution and global warming |
Clean and pollution-free |
|
Cost |
Costly to extract, transport, and process |
Free (but requires solar devices) |
|
Convenience |
Easy to store, transport, and use anytime |
Available only in daytime, depends on weather |
Q5. Compare and contrast biomass and hydro-electricity as sources of energy.
Ans:
|
Point of Comparison |
Biomass |
Hydro-electricity |
|
Source |
Organic matter like wood, crop waste, dung |
Flowing or falling water |
|
Renewability |
Renewable, but causes smoke and pollution |
Renewable and pollution-free |
|
Cost |
Low cost, locally available |
High cost due to dam construction |
|
Energy Output |
Produces less energy |
Produces large amount of energy |
|
Impact |
Can cause indoor air pollution |
Dams may affect local habitats |
Q6. What are the limitations of
extracting energy from
(a) the wind?
(b) waves?
(c) tides?
|
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|---|---|---|---|---|---|---|---|---|---|
| Q7. On
what basis would you classify energy sources as (a) renewable and non-renewable? (b) exhaustible and inexhaustible? Are the options given in (a) and (b) the same? |
Ans:
(a) Renewable and Non-renewable:
- If a source of energy can be replenished naturally and never gets exhausted, it is renewable (e.g., solar, wind, water).
- If a source of energy is limited and will get exhausted after use, it is non-renewable (e.g., coal, petroleum, natural gas).
(b) Exhaustible and Inexhaustible:
- Sources that can be used up completely are exhaustible (e.g., fossil fuels).
- Sources that are unlimited and never end are inexhaustible (e.g., sunlight, wind).
Are they the same?
Yes, both terms mean the same, just
expressed differently.
Q8. What are qualities of an ideal source of energy?
Ans: Qualities of an ideal source of energy:
- Easily available.
- Cheap and economical.
- Produces a large amount of energy.
- Easy to store and transport.
- Safe to use.
- Causes little or no pollution.
Q9. What are the advantages and disadvantages of using a solar cooker? Are there places where solar cookers would have limited utility?
Ans: Advantages of a solar cooker:
- Uses sunlight, which is free and renewable.
- Eco-friendly, no smoke or pollution.
- Food retains nutrients as it is cooked at moderate temperature.
- Saves conventional fuels like LPG, coal, or wood.
Disadvantages of a solar cooker:
- Works only in daytime with good sunlight.
- Cannot be used during cloudy or rainy days.
- Cooking is slow compared to LPG or electric stoves.
- Cannot be used for frying or making chapatis easily.
Places with limited utility:
Solar cookers have limited use in cold, cloudy, or rainy regions, and in places
where sunlight is not available throughout the year.
Q10. What are the environmental consequences of the increasing demand for energy? What steps would you suggest to reduce energy consumption?
Ans: Environmental consequences of increasing energy demand:
- Burning fossil fuels causes air pollution and releases greenhouse gases.
- Leads to global warming and climate change.
- Mining and extraction of fuels damage land and ecosystems.
- Deforestation for fuel reduces biodiversity.
- Nuclear waste disposal creates radiation hazards.
Steps to reduce energy consumption:
- Use renewable sources like solar, wind, and hydro power.
- Switch to energy-efficient appliances (LED bulbs, star-rated devices).
- Practice energy conservation – switch off lights, fans, and machines when not in use.
- Promote public transport, carpooling, cycling, and walking.
- Encourage afforestation and protect natural resources.