CBSE Class 10 Science Chapter 14: Sources of Energy NCERT Solutions

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NCERT Solutions PDF Class 10 PDF

This chapter delves into the fundamental concepts of energy sources, crucial for Class 10 Science students. It explores what constitutes a good source of energy, the characteristics of a good fuel, and practical considerations for heating food. The solutions also address the significant disadvantages associated with fossil fuels, such as air pollution and the greenhouse effect, highlighting their non-renewable nature. Understanding the need for and exploring alternate sources of energy is a key focus. The chapter further explains how traditional methods of harnessing wind and water energy have been modernized for greater convenience and efficiency. These NCERT Solutions provide clear, step-by-step explanations to help students grasp these vital topics, aiding in effective exam preparation and a deeper understanding of energy resources.

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Quick info

BoardCBSE
ClassClass 10
SubjectScience
Session2026
LanguageEnglish
TypeNCERT Solutions
ChapterChapter 14

Chapter summary

Chapter 14 of the CBSE Class 10 Science NCERT Solutions focuses on various sources of energy. It defines the criteria for a good energy source and a good fuel, discusses practical applications like heating food, and elaborates on the environmental drawbacks of fossil fuels. The chapter emphasizes the importance of exploring and utilizing alternative energy sources and explains the modern applications of wind and water energy. These solutions offer clear explanations for all questions, reinforcing key concepts.

Learning outcomes

  • Define the characteristics of a good source of energy.
  • Identify the properties of a good fuel.
  • Explain the disadvantages of using fossil fuels.
  • Understand the necessity of alternative energy sources.
  • Describe the modern methods of utilizing wind and water energy.

Topics covered

Paper topics

  • Sources of Energy
  • Characteristics of a Good Energy Source
  • Good Fuel
  • Fossil Fuels
  • Disadvantages of Fossil Fuels
  • Air Pollution
  • Greenhouse Effect
  • Acid Rain
  • Non-renewable Energy
  • Alternate Sources of Energy
  • Wind Energy
  • Water Energy

Important topics

  • Characteristics of a Good Source of Energy
  • Disadvantages of Fossil Fuels
  • Need for Alternate Sources of Energy
  • Harnessing Wind and Water Energy
  • Greenhouse Effect and Acid Rain

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Questions and Solutions

Question 1

What is a good source of energy?
Solution: A good source of energy possesses several key qualities that make it practical and sustainable for use. Firstly, it must be easily available, meaning it can be accessed without significant difficulty. Secondly, it should be capable of doing a large amount of work or producing substantial heat relative to its volume or mass, ensuring efficiency. Thirdly, it needs to be easy to store and transport, allowing for convenient distribution and use. Furthermore, a good energy source should be economical, meaning it is affordable for widespread application. Finally, and crucially in today's world, it should cause minimal environmental pollution, such as low emissions of harmful gases or waste products.

Question 2

What is a good fuel?
Solution: A good fuel is characterized by its ability to release a significant amount of heat energy when it undergoes combustion (burning). Importantly, it should burn cleanly, producing minimal smoke or harmful by-products that contribute to air pollution. Additionally, like a good energy source, a good fuel should be readily available and easily obtainable to ensure its practical utility.

Question 3

If you could use any source of energy for heating your food, which one would you use and why?
Solution: For heating food, a practical and efficient choice would be LPG (Liquefied Petroleum Gas) or CNG (Compressed Natural Gas), or electricity. These sources are preferred because they offer a high thermal efficiency, meaning a large portion of the energy supplied is converted into heat for cooking. They also generally cause less pollution compared to burning solid fuels like wood or coal. Furthermore, their use is convenient, as they can be easily controlled and supplied through pipes or directly to appliances, making the process of heating food straightforward and effective.

Question 1

What are the disadvantages of fossil fuels?
Solution: Fossil fuels, such as coal and petroleum, have several significant disadvantages. Primarily, their combustion releases harmful pollutants into the atmosphere. Burning these fuels produces acidic oxides of carbon, nitrogen, and sulphur. These oxides can lead to acid rain, which damages water bodies, soil, and ecosystems. Moreover, the release of carbon dioxide (CO2) contributes to the greenhouse effect, trapping heat in the atmosphere and causing global warming. Another major disadvantage is that fossil fuels are non-renewable resources; they are finite and cannot be replenished at a rate comparable to their consumption, meaning they will eventually run out.

Question 2

Why are we looking at alternate sources of energy?
Solution: The primary reason for seeking alternate sources of energy is the non-renewable nature of traditional fossil fuels like coal, petroleum, and natural gas. These resources are finite and are being depleted at an alarming rate due to high global demand. If current consumption patterns continue, these valuable energy reserves will eventually be exhausted. Therefore, to ensure a sustainable energy supply for future generations and to mitigate the environmental damage caused by fossil fuels, it is essential to develop and utilize alternative, renewable energy sources.

Question 3

How has the traditional use of wind and water energy been modified for our convenience?
Solution: The traditional uses of wind and water energy have been significantly modernized to enhance convenience and efficiency. For water energy, large dams are constructed in hilly regions to store vast quantities of water at a height. This stored water is then channeled through pipes to turbines located at the base of the dam, driving a hydropower plant to generate electricity. Similarly, for wind energy, windmills are now commonly used not just for grinding grain or pumping water, but specifically to rotate the blades of turbines connected to electric generators. This modification allows for the efficient conversion of wind's kinetic energy into electrical energy, meeting modern energy demands.

Common mistakes

  • Confusing the properties of a good energy source with those of a good fuel.
  • Underestimating the environmental impact of fossil fuels.
  • Not fully grasping the concept of non-renewable energy sources.
  • Failing to connect traditional energy uses with modern technological advancements.

Revision tips

  • Create a checklist of qualities for a good energy source and fuel.
  • List the specific environmental problems caused by fossil fuels.
  • Draw diagrams to illustrate how wind and water energy are harnessed.
  • Compare and contrast renewable and non-renewable energy sources.
  • Focus on the 'why' behind needing alternate energy sources.

Practice MCQs

Q1. Which of the following is NOT a characteristic of a good source of energy?

Q2. What is a major disadvantage of burning fossil fuels?

Q3. Why are we exploring alternate sources of energy?

Q4. How is wind energy traditionally modified for convenience?

Q5. Which gas released from burning fossil fuels contributes to the greenhouse effect?

Frequently asked questions

What makes a source of energy 'good' according to NCERT Class 10 Science?

A good source of energy is easily available, economical, easy to store and transport, does a large amount of work per unit mass/volume, and causes minimal environmental pollution.

What are the main problems with using fossil fuels?

Fossil fuels are non-renewable, contribute to air pollution through acidic oxides (causing acid rain), and release carbon dioxide, which causes the greenhouse effect.

Why is it important to find alternate sources of energy?

Fossil fuels are finite and are being consumed rapidly. Alternate sources are needed to ensure a sustainable energy supply for the future and to reduce environmental damage.

How has the use of wind and water energy been modernized?

Large dams store water for hydropower plants, and windmills are used to generate electricity by turning turbines, making these traditional sources more efficient and convenient.

What is the role of CO2 from fossil fuels?

Carbon dioxide released from burning fossil fuels traps heat in the atmosphere, leading to the greenhouse effect and global warming.

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