Important Questions for CBSE Class 10 Science Chapter 14 Sources of Energy 2024-25

Very Short Answer Questions.                                                            (1 Mark)

1. A solar cooker may not cook food if.

(a) Interior of the box and the container of food are perfectly shining.

(b) Glass sheet over the box is not closed.

(c) Solar cooker is placed in the shade.

(d) All the above.

Ans: (d) All the above.

2. Radiations that are harmful to the living organisms are

(a) Infrared radiation.

(b) ultraviolet radiations

(c) Visible radiation.

(d) Microwaves

Ans: (b) ultraviolet radiations

3.Solar cells are made of

(a) Metals

(b) Insulator

(c) Semiconductors  

(d) none of these

Ans: (c) Semiconductors

4. The main constituent of CNG is

(a) butane

(b) methane

(c) ethane

(d) propane

Ans: (b) methane

5. Which of the following is not a biomass energy source?

(a) gobar gas

(b) coal

(c) wood

(d) nuclear energy

Ans: (d) nuclear energy

6. Which of the following is more environmentally friendly?

(a) Burning of coal

(b) burning of firewood

(c) burning of charcoal

(d) Burning of diesel.

Ans: (c) burning of charcoal

7. Major problem in harnessing nuclear energy is to

(a) split heavy nucleus

(b) sustain nuclear reactions

(c) Convert nuclear energy into electricity

(d) dispose of spent fuel safety.

Ans: (d) dispose of spent fuel safely.

8. Fusion reaction is also known as

(a) chemical reaction

(b) elastic scattering

(c) thermonuclear reaction

(d) photonuclear reaction

Ans: (c) thermonuclear reaction

9. India exploded her first underground nuclear device at

(a) Ranchi

(b) Kota

(c) Jaipur

(d) Pokhran

Ans: (d) Pokhran

10. Although charcoal is clean and a better source of heat energy yet it cannot be used as a domestic fuel because it

(a) cause environmental pollution

(b) produce less heat energy

(c) cannot be stored easily

(d) is an expensive fuel

Ans: (d) is an expensive fuel

11. 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

Ans: (b) a cloudy day

12. Which of the following is not an example of bio-mass energy?

(a) wood

(b) gobar-gas

(c) nuclear energy

(d) coal

Ans: (c) nuclear energy

13. 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

14. In the given flow chart of energy conversion during hydroelectric power generation, fill in the blanks with an appropriate answers.

Flow Chart of Energy Conversion

Ans: Dynamo.

15. Consider two solar cookers, one covered with a plane glass plate and the other kept open. Which of the two cookers would be more efficient and why?

Ans: Because of the greenhouse effect, a solar cooker with a covered glass slab is recommended.

16. Give one reason how increasing dependence on nuclear power generation is a the threat for future generations?

Ans: Radiation emitted during a leak might cause genetic changes or lead to nuclear waste disposal.

Short Answer Questions.                                                                    (2 Marks)

17. Hydropower is a renewable source of energy. Justify.

Ans: Because it is obtained from a renewable source of energy, namely the sun, hydropower is a renewable form of energy.

18. Write two qualities of an ideal source of energy?

Ans: The two features of an ideal energy source are: 

(i) It does not pollute the environment. 

(ii) It is cost-effective.

19. What are the advantages of nuclear energy?

Ans: Nuclear energy has the following advantages:

(i) A small amount of fuel produces a great amount of energy.

(ii) Once put into a nuclear power plant, nuclear fuel produces a significant amount of energy for a longer period of time.

20. Name two activities in our daily life in which solar energy is used?

Ans: (i) To use solar cookers to prepare meals.

(ii) To dry garments and grains of food.

21. Write two advantages of using a solar cooker?

Ans: When food is cooked inside a solar cooker, it is,

(i) pollution-free and (ii) nutritionally valuable.

22. Suggest two ways to reduce energy consumption?

Ans: (i) Burning fuels must be extinguished as soon as they are no longer needed.

(ii) When leaving your room, make sure all lights, tubes, fans, and other electrical equipment are turned off.

23. What is Geothermal Energy? Write its Advantages?

Ans: Geothermal energy is the heat energy obtained from hot rocks found in the earth's crust. Geothermal energy has the following advantages:

(i) It is environmentally benign.

(ii) It is less expensive to convert geothermal energy into electricity.

24. Why are many thermal power plants set up near coal or oil fields?

Ans: Thermal power stations are typically built near coal or oil fields to ensure that fuel is readily available and that air pollution caused by transportation is minimized.

25. What is a good fuel?

Ans: A good fuel is one that produces more heat when burned, is readily available at a low cost and does not pollute the environment.

26. If you could use any source of energy for heating your food, which one would you use and why?

Ans: For heating your food, we will utilize LPG/PNG gas or electricity, which are both pollution-free and high in calorific value.

27. What kind of mirror –concave or convex or plain –would be best suited for use in a solar cooker? Why?

Ans: High concave mirrors are ideal for use in solar cookers because they concentrate a large quantity of solar radiation into a small surface area, allowing for rapid temperature rise.

28. Can any source of energy be pollution-free? Why or why not?

Ans: No, the energy source does not pollute the environment in any way. A source of energy is considered pollution-free if it does not pollute the environment during its operation or when devices that use it are assembled. It's possible that solar cell technology polluted the environment.

29. Hydrogen has been used as rocket fuel; would you consider it a clear fuel than CNG? Why or why not?

Ans: Hydrogen is a cleaner fuel since it produces non-polluting water vapor when burned. However, due to hydrogen's explosive nature, storage and transportation are difficult.

30. The cost of production of electricity in a thermal power station located in Bihar/Tharkliand/Orissa is less than in Gujarat/Maharashtra. Do you agree? Justify your answer.

Ans: This is due to the fact that coal is readily available in Bihar, Jharkhand, and Orissa, whereas it must be transported for any thermal power plant in Gujarat or Maharashtra.

31. Which of the following sources of electricity involves more running expenses and why? The thermal power station, Hydropower station, solar cells, or Geothermal source.

Ans: Due to the constant usage of coal, thermal power plants have higher operating costs.

32. Why is there so much emphasis on changing over from petrol/diesel-driven automobiles to CNG-driven vehicles?

Ans: When CNG is burned, it simply creates CO2 and water. It does not emit any smoke. It does not leave any unburned hydrocarbons, lead particles, or other contaminants behind.

33. Which of the following is not an example of the biomass energy source?

(a) Wood (b) gobar gas (c) atomic energy (d)coal.

Ans: (c)Atomic energy. Atomic energy isn't a biomass-based energy source.

34. How is the supply of electricity maintained in a windmill when there is no wind? In a solar panel when there is no sun?

Ans: The energy produced is stored in a battery in both circumstances. When there is no wind, as with a windmill, and when there is no sun, as with a solar panel, this battery generates electricity.

35. Can any source of energy be pollution-free? Why or why not?

Ans: There is no such thing as a pollution-free energy source because all energy sources affect the environment in some way. Although the energy source itself is pollution-free, the device's assembly may have harmed the environment. As a result, no energy source can be said to be pollution-free in the strictest sense.

36. Though a hot iron emits radiation, yet it is not visible in the dark, why?

Ans: Hot iron generates infrared photons that are invisible to the naked eye.

37. Define OTE (ocean thermal energy).

Ans: OTE refers to the energy that is available as a result of the temperature difference between the ocean's surface and deeper layers.

38. Give two ways in which animal dung can be used as fuel. Which way is better and why?

Ans: As both a dung cake and a biogas source. Biogas is preferable since it emits less pollution and provides more calories.

39. The wind velocity at three places A, B, and C are 5Km/hr, l5Km/hr, 10Km/hr respectively. Which is the most suitable place for installing windmills & why?

Ans: B, The maximum speed allowed is 15 km/h. It will not operate at a slower speed.

It is possible that the blades will shatter if the speed is too high.

40. What are two advantages of charcoal over wood as fuel?

Ans: The two advantages of charcoal over wood as fuel are;

(i) Pollution-free (ii) Contains high calorific value

41. Mention any two reasons, why wood is not preferred as fuel.

Ans: (i) Wood burning pollutes the environment. 

(ii) Deforestation would result from excessive consumption of wood.

Short Answer Question                                                                      (3 Marks)

42.(a) Distinguish between renewable and non-renewable sources of energy?

(b) Choose the renewable source of energy from the following list: coal, biogas, sun,  natural gas.

Ans: (a)  Difference Between Renewable and Non-Renewable Sources:

(b) Sun and biogas are renewable sources of energy.

42. (a) Name the device used to convert

     (i) Solar energy into heat and

     (ii) solar energy into electricity.

(b) Explain the working of the windmill

Ans: (a) (i) A solar cooker converts solar energy into heat.

(ii) A solar cell converts solar energy into electricity.

(b) The kinetic energy of the wind is used to rotate the blades of the windmill when the wind blows at a minimum speed of 15 km/hr. The blades' rotational energy is used to rotate the generator's armature, which then produces electricity.

43. What is biogas? How can biogas be obtained? Why the use of biogas obtained from cow dung is advised to use as compared to cow dung cakes?

Ans: Biogas is a mixture of gases, including methane and carbon dioxide. It's made from a biogas plant's aerobic breakdown of cow dung, plants, and animal wastes. Biogas is recommended for burning instead of cow dung cakes because;

(i) it does not pollute the air and (ii) it is a less expensive source of energy.

44. What are the limitations of extracting energy from

(a) the wind

(b) waves

(c) tides

Ans:

1. Wind energy is insufficient to power big machinery and is also limited to a certain location.

2. Only if a strong wind blows continuously across the sea can the energy of the waves be extracted.

3. A tidal power plant can harvest a huge amount of tidal energy from the water levels during high and low tide.

45. Name three forms in which energy from the ocean is made available for use. What are

OTEC power plants? How do they operate?

Ans: 

1. Muscular energy is obtained from the food we consume to execute various actions such as taking a bath or climbing stairs.

2. Fossil fuel energy is utilized to get to school by bus or car, which comes from fossil fuels such as gasoline, diesel, and compressed natural gas (CNG).

3. Chemical energy is obtained from breakfast and the food we eat.

46. List three forms of energy we use when we wake up from morning till we reach school. Also from where do, we get these different forms of energy?

Ans: 

1. Tidal energy

2. Ocean waves energy

3. Ocean thermal energy

Ocean thermal energy conversion plants, or OTECs, are power facilities that convert ocean thermal energy into electricity. Boiling liquids like chlorofluorocarbons or ammonia or are necessary to operate OTEC at a temperature difference of 20℃ or more between the surface water of the ocean and the inner water of the ocean. 

The high-pressure vapors of the liquid rotated the turbine of the generator, which produced energy.

47. Compare and contrast bio-mass and hydro-electricity as sources of energy. The production cost of hydroelectricity is cheaper than the electricity produced in a thermal power station. Explain why?

Ans: The points of difference between biomass and hydroelectricity are: 

Coal is burned to generate electricity in a thermal power plant, whereas hydroelectricity is generated by letting waterfall on turbines. Although river water is cheap, the cost of extracting and transporting coal is extremely costly.

48. What kind of mirror concave, convex, or plane would be best suited for use in a solar cooker. Why? What is the role of glass sheet used in a solar cooker? Also, write two disadvantages of using a solar cooker?

Ans: The use of a concave mirror in a solar cooker is ideal because it concentrates all of the sunlight to a single place following the reflection of the mirror, raising the temperature of that point.

The infrared or heat radiation that enters the box cannot escape through the plane glass plate, heating the box and creating a greenhouse effect.

The Following are two Drawbacks of Utilizing a Solar Cooker:

1. Food cannot be cooked at night or on a cloudy day.

2. Using a solar cooker, food cannot be prepared quickly.

49. What is a good source of energy?

Ans: The following characteristics should be present in a good source of energy:

1. Its calorific value should be high.

2. It should be readily available.

3. It should be simple to transport and store.

4. It should not pollute the environment.

5. It should be cost-effective.

50. What are the disadvantages of fossil fuels?

Ans: The following are some of the drawbacks of fossil fuels:

1. Fossil fuels are nonrenewable energy sources.

2. Acid rain is caused by sulfur and nitrogen oxides produced by fossil fuel combustion.

3. The greenhouse effect is caused by carbon dioxide.

4. Pollution is caused by the use of fossil fuels.

51. Why are we looking at alternate sources of energy?

Ans: Fossil fuels are non-renewable energy sources that have finite reserves. As a result, we must protect them. We may soon run out of energy if we continue to consume these resources at the current rate. To avoid a situation like this, we're exploring other energy sources.

52. How has the traditional use of wind and water energy been modified for our convenience?

Ans: Large dams are erected in hilly places to hold massive amounts of water at a height in order to harness the energy of flowing water. Hydroelectricity is generated using this water. Windmills are used to transform wind energy into electricity, which is then used to generate electricity.

53. What are the limitations of the energy that can be obtained from the oceans?

Ans: Limitations of Energy Derived from Oceans: 

1. The cost of installing power plants is exceedingly high, and plant efficiency is quite low.

2. There are only a few places where tidal energy dams can be developed.

3. Ocean-based power plants will necessitate extensive ongoing maintenance.

54. What is Geothermal Energy?

Ans: Geothermal energy is the heat energy found in particular areas of the earth known as hot spots. Steam is produced when subsurface water comes into contact with the heated point. This steam is piped to a turbine, where it is used to generate energy.

55. What are the advantages of nuclear energy?

Ans: The Advantages of Nuclear Energy are: 

1. It is one of the most carbon-free energy sources available

2. It's one of the solutions to the energy shortage.

3. It's critical to our fight against climate change and greenhouse gas emissions.

4. Reliable and economical.

56. Name two energy sources that you would consider to be renewable. Give reasons for your choices.

Ans:  Wind energy, Solar Energy, Ocean Energy, and Other Renewable Energy Sources Include:

1. These sources of energy are abundant in our natural surroundings.

2. These energy sources will not be depleted because their supply is abundant and the amount of usable energy extracted from them is minimal.

57. Give the names of two energy sources that you would consider to be exhaustible. Give reasons for your choices.

Ans: Both coal and petroleum are finite energy sources. These fuels took millions of years to develop, and there are only a few reserves left. These reserves will be depleted very quickly if we continue to use them as we are.

58. Compare and contrast fossils fuels and the Sun as direct sources of energy?

Ans:  The Differences Between Fossil fuels and Sun Energy are as Follows:

59. Compare and contrast biomass and hydroelectricity as sources of energy?

Ans: The differences between Biomass and Hydroelectricity  are as follows:

60. What are the qualities of an ideal source of energy?

Ans: Ideal sources of energy should have the following characteristics: 

1. they should be easily available, inexhaustible, and renewable, and the cost of capturing energy should be reasonable.

2. It must be simple to store and move.

3. It must have high-calorie content.

4. It should be free of pollution.

61. H2 has been used as rocket fuel. Would you consider it as a cleaner fuel than CNG? Why or why not?

Ans: When H2 is burned in the presence of oxygen, the only result is water, which has a high heat energy content. Water is non-polluting, whereas CNG releases carbon monoxide and water when burned. Carbon monoxide is not a pollutant, but it does cause a rise in temperature (global warming). This rise is known as the greenhouse effect, and it will have an impact on polar ice, putting human life at risk. So, H2 is a cleaner fuel than CNG.

62. Why is biogas a better fuel than animal dung-cakes.

Ans: Biogas is a superior fuel to animal dung cakes because of the following reasons:

1. Animal dung-cake burning produces a lot of pollutants, whereas biogas is a smokeless fuel.

2. Biogas has a significantly higher calorific value than animal dung cakes.

3. When animal dung cakes are burned, they leave a residue, whereas biogas does not.

63. How the difference in temperature helps to harness energy from the ocean?

Ans: The temperature difference aids in the production of energy in ocean -thermal -energy conservation plants that operate at temperatures of 200 C or higher. A volatile liquid is boiled in heated surface water. The liquid-vapora is utilized to power the generator's turbine, and cold water from the depths of the ocean is pushed up to condense the vapor back into liquid.

64. Write three reasons why the construction of Tehri Dam on river Ganga and Sardar Sarovar project on river Narmada is opposed by local people and environmentalists?

Ans:

1. Disruption of ecological equilibrium.

2. Problems with rehabilitation and agricultural land loss.

3. Plant degradation in water results in the formation of greenhouse gases.

65. Write three environmental consequences of the various source of energy we used?

Ans: The three environmental consequences of the various source of energy we used are; (i) Pollution (ii) Greenhouse effect (iii) Inefficient usage of natural resources 

Long Answer Questions  (5 Marks)

66. A student constructed a box-type solar cooker. He found that it did not work efficiently. What could this be due to? Give any four possible mistakes in the construction and operation of the solar cooker

Ans: He could have made some mistakes:

1. The solar cooker's interior is not painted black.

2. Plastic sheet is used to cover it instead of the glass sheet.

3. There is no insulation in the solar cooker.

4. No black containers were utilized.

In a solar cooker, the maximum temperature is 140℃.

67. 

1. What is biogas? Name two main combustible components of biogas?

2. What is the use of spent slurry in a biogas plant?

3. Name the microorganisms responsible for the fermentation of slurry in the digester?

Ans: 

1. Biogas is a mixture of gases produced when animal feces and water are allowed to decay in the absence of oxygen. Methane and hydrogen gas are the two combustible components of biogas.

2. Biogas plant wasted slurry is high in nitrogen and phosphorus, which are essential for plant growth, and hence can be utilized as manure.

3. Anaerobic microorganisms are responsible for the fermentation of slurry in the digester. 

68. What are the limitations of extracting energy from:

(i) the wind? (ii) waves? (iii) tides?

Ans: (i) Wind:

1. It isn't always present.

2. It necessitates a huge land area.

3. A windmill cannot be installed in every location since it requires a minimum wind speed of 15 km/hr to operate.

(ii) Waves: 

1. Wave energy would only be feasible if waves are quite powerful.

2. Setting up equipment to capture wave energy is expensive.

(iii) Tides:

1. Only a few sea coasts throughout the world have adequate places for tidal energy harvesting.

2. The fact that the tides rise and fall just twice a day is insufficient to generate electricity on a continual basis.

69. On what basis would you classify energy sources as

1. renewable and non-renewable?

2. exhaustible and inexhaustible?

Are the options are given in (a) and (b) the same.

Ans: 

1. Renewable energy sources are ones that can be used again after being depleted.

Non-renewable energy sources are those that will be depleted and cannot be replenished at some point in the future.

2. Exhaustible energy sources are ones that will be depleted at some point and cannot be replenished. Energy sources that are inexhaustible are those that can be regenerated. They are limitless due to certain continuous or recurring currents of energy. In both cases, options are the same.

70. What are the advantages and disadvantages of using a solar cooker? Are there places where solar cookers would have limited utility?

Ans: Solar Cookers have the Following Advantages:

1. There are no fuel costs.

2. It is environmentally friendly, with no ash or other residue.

3. Cooking is healthy and hygienic.

The disadvantages of using a solar cooker are:

1. It takes a long time to cook.

2. It isn't possible to use it all of the time.

3. The capabilities of a solar cooker are restricted.

71. What are the environmental consequences of the increasing demand for energy? What steps would you suggest to reduce energy consumption?

Ans: The usage of fossil fuels is mostly meeting the rising demand for energy. However, these fuels are finite and non-renewable energy sources. Furthermore, using fossil fuels pollutes the air. Acid rain is caused by the release of acidic oxides, which have an impact on our water and soil resources. These gases also contribute to the greenhouse effect, which raises global temperatures. We should live a simple, natural life to limit our energy use. Instead of utilizing an air conditioner in a closed room, we could live in a space with enough windows.

Important Questions For Class 10 Science Sources of Energy

The important questions class 10 science chapter 14 Pdf provided here include all questions with detailed answers to aid students in securing good scores in their examinations.

Sources of Energy Class 10 Important Questions:

The sources of energy class 10 important questions will enable students to answer every question according to the need of the board exam from the chapter with a detailed understanding. The important questions class 10 science chapter 14 Pdf provided here is useful for students in learning every concept of chapter 14 precisely. Chapter 14 of class 10 science deals with the sources of energy. The sources of energy chapter will give a deep insight into the concept of energy and energy conversions.

The class 10 science chapter 14 important questions study material is made for students to easily understand and it will help students to learn the concepts of energy sources and other topics more precisely. The important questions for class 10 science chapter 14 will cover all the questions from the textbook along with the extra questions of chapter 14 class 10 science which will lead students to secure good grades in their board examinations. To begin with, the sources of energy class 10 important questions students are required to be well versed in all the concepts from this chapter. Students are advised to revise thoroughly with the help of revision notes and the extra questions of chapter 14 class 10 science. Let us have a look at some key points from chapter 14 of class 10 science:

• Chapter 14 of class 10 physics mainly focuses on the different forms of energy and their utilization.

• Students will learn about what are conventional sources of energy, what are their importance, and the need for the conventional source energy.

• In this chapter, students will also learn about different types of energy sources, and how the conversion of energies is performed.

• The chapter introduces the concept of solar energy in detail. We will understand the importance of solar energy and how solar energy is converted into electricity as a replacement for the regular power supply.

• In this chapter, we will come across some interesting experiments like the construction of solar panels and their importance.

• Chapter 14 enables us to understand solar energy, and why do we need the conversion of energies.

• In this chapter, students will also learn about nuclear energy. The chapter focuses on nuclear fission and the nuclear fusion process Students will also learn the differences between these two processes.

These are some key points from chapter 14 of class 10 physics. Students are advised to learn all the topics from the chapter without fail. For boosting their exam preparation students should use the study materials available on the Vedantu website. The important questions of class 10 science chapter 14 Pdf help students to achieve their desired score. Students who are aiming for good grades must start their preparation with proper strategy and proper study materials such as sources of energy class 10 important questions. For more detailed information students are advised to download the revision notes, NCERT solutions for class 10 science, from the Vedantu website which are available in Pdf format for easy access.

What are the Benefits of Important Questions from Vedantu for Class 10 Science Chapter 14 - Source of Energy

• Focus on key topics for efficient studying.

• Prepares students for exams and reduces anxiety.

• Reinforces understanding of fundamental concepts.

• Teaches effective time management.

• Enables self-assessment and progress tracking.

• Strategic approach for higher scores.

• Covers a wide range of topics for comprehensive understanding.

• Supports exam preparation and boosts confidence.

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