Class 10 Science Chapter 14 Solution – Sources of Energy | SEBA Assam

Class 10 Science Chapter 14 – Sources of Energy – All Textual Solutions | ASSEB Assam (English Medium)

Class 10 Science Chapter 14 – Sources of Energy Complete Textual Solutions (ASSEB / SEBA Assam – English Medium)

The fourteenth chapter of the Class 10 Science curriculum, ‘Sources of Energy’, is a vital and practical topic that connects science with our daily lives and the environment. These complete textual solutions (Class 10 Science Chapter 14 Textual Question Answer) have been prepared based on the latest ASSEB (Assam State School Education Board) syllabus and the newest guidelines of the National Education Policy (NEP) for the upcoming board exams. This comprehensive collection includes Very Short Answers (VSA), Short Questions, Long Answers, and detailed conceptual explanations. At Ospin Academy, these solutions are provided in a simple, accurate, and completely exam-oriented format.

This chapter explores the characteristics of a good source of energy, categorizing them into conventional (fossil fuels, thermal, hydro) and non-conventional sources (solar, wind, biomass, nuclear). It also addresses the environmental consequences of our energy choices and the need for sustainable, renewable energy alternatives. It is highly essential for matric candidates to clearly understand these real-world energy concepts. Our textual solutions cover all textbook exercise questions, in-text questions, and additional exam-focused questions to ensure students are fully equipped for their examinations.

What you will learn and get from these textual solutions:

• Clear distinctions between renewable and non-renewable, as well as conventional and non-conventional sources of energy.
• Flawless answers for 1-mark VSA (objective type) and 2-3 mark short questions regarding the advantages and disadvantages of fossil fuels.
• Standard and easy-to-understand solutions explaining the working of solar cookers, solar panels, and biogas plants.
• Detailed information on the hazards of nuclear energy and the environmental consequences of energy extraction.
• Solutions to all important questions along with the latest pattern MCQ questions as per the new syllabus.

Special features of these textual solutions by Ospin Academy:

• Complete textual solutions prepared strictly according to the latest ASSEB new syllabus.
• 100% accurate, high-quality notes written in simple English, making it easy for students to understand and memorize (Class 10 Science Notes).
• Simplified answers specially designed for Quick Revision right before the examinations.
• A special compilation of extra important conceptual questions that are highly likely to appear in the board exams.

Keeping in mind the academic upliftment of students, Ospin Academy has brought forward these special textual solutions. Start your matric exam preparation now and step forward towards scoring the highest marks in Science.

Class 10 Science

Chapter: 14                                                  Ospin Academy

Source of Energy

Textual Questions and Answers

1. What is a good source of energy?

Answer: A good source of energy is one that:

(a) Generates significant heat per unit mass.

(b) Provides a large amount of work per unit mass.

(c) Is readily available.

(d) Can be easily stored and transported.

(e) Is cost-effective.

(f) Produces minimal smoke or pollution..

2. What is a good fuel?

Answer: A good fuel:

(a) Is easily available in nature.

(b) Has a high calorific value, providing more energy per unit mass.

(c) Burns efficiently without leaving residues.

(d) Produces little to no smoke and is environmentally friendly.

(e) Is economical and affordable.

(f) 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.

4. What are disadvantages of fossil fuels?

Answer:

Disadvantages of fossil fuels are:

(a) Air pollution.

(b) 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

(c) Global warming- the greenhouse effect of gases like carbon dioxide.

(d) The fossil fuels are non-renewable sources of energy.

5. 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.

6. 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.

7. 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.

8. 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:

(a) The tidal energy is affected by the relative positions of the earth, the sun, and the moon.

(b) High dams are required for converting tidal energy into power.

(c) Strong waves are necessary to generate electricity from wave energy.

(d) A temperature difference of more than 20°C between hot surface water and cool water at depth is required to store ocean thermal energy.

9. 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.

10. What are the advantages of nuclear energy?

Answer: Nuclear energy is preferred to fossil energy, hydro energy, thermal energy etc for the following reasons.

(a) One of the most low-carbon energy sources.

(b) It also has one of the smallest carbon footprints.

(c) It’s one of the answers to the energy gap.

(d) It’s essential to our response to climate change and greenhouse gas emissions.

(e) Reliable and cost-effective.

11. 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.

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

Answer: Hydrogen is regarded as a cleaner fuel than CNG because the combustion of hydrogen produces only water, which is completely harmless to the environment. In contrast, the burning of CNG produces carbon dioxide gas, which contributes to the heating of the environment over a long period of time.

The increasing demand for energy has several environmental consequences. The combustion of fossil fuels produces acid rain which damages plants, soil and aquatic life. The burning of fossil fuels also increases the amount of greenhouse gas carbon dioxide in the atmosphere. The cutting down of trees from forests for obtaining firewood causes soil erosion and destroys wildlife. The construction of hydro-power plants disturbs the ecological balance. Nuclear power plants also increase radioactivity in the environment.

While choosing a source of energy, several factors should be kept in mind. These include the ease of extracting energy from the source, the cost of extracting energy from the source, the efficiency of the technology available to extract energy from the source, and the damage to the environment that may be caused by using that source.

13. 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:

(a) 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.

(b) 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.

14. 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:

(a) 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.

(b) 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.

Exercise Questions and Answers

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.

Answer: (c) Nuclear energy.

4. Compare and contrast fossil fuels and the Sun as direct sources of energy.

Answer: 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: Biomass and hydroelectricity are both renewable sources of energy. However, when biomass is used as a fuel by burning, it causes air pollution, whereas hydroelectricity generation does not produce pollution. Another difference is that biomass energy can be obtained without using any special equipment, while hydroelectricity can be produced only by establishing hydro-power plants.

6. What ar the limitations of extracting energy from —

(a) The wind?

Limitations of wind energy:

(i) A large open area is required to install many windmills so that sufficient electricity can be generated.

(ii) Wind energy is not available everywhere and it is also not available all the time because wind does not blow continuously.

(iii) The speed of the wind must be sufficiently high; otherwise electricity cannot be generated efficiently.

(iv) The initial cost of setting up wind farms is also high.

(b) Waves?

Answer: 

Limitations of extracting energy from waves:

(i) Wave energy can be used only in those places where the waves are very strong.

(ii) This limits its use because suitable locations are very few.

(iii) The strength of waves also depends on time and weather conditions, so energy cannot be produced continuously.

(c) Tides?

Answer:

Limitations of tidal energy:

(i) The cost of constructing tidal energy dams is very high and such dams cannot be constructed everywhere.

(ii) A large amount of silt gets deposited in the basins of the dams which reduces their efficiency.

(iii) Suitable locations for building tidal dams are limited.

7. On what basis would you classify energy sources as:

Renewable and non-renewable?

Answer: Energy sources are classified as renewable and non-renewable on the basis of their availability and the ability to be replenished naturally. The energy sources that can be regenerated naturally are called renewable sources of energy.

Renewable energy:

(i) A renewable source of energy is one that can replenish itself naturally in the environment.

(ii) Examples include solar energy, wind energy, flowing water and biomass.

(iii) Energy from these sources is obtained from natural resources that can be regenerated over time, so they are considered renewable.

Non-renewable energy:

(i) Non-renewable energy sources are those which will get exhausted after a few hundred years.

(ii) Examples of non-renewable energy sources include coal, petroleum, and natural gas.

(iii) Most of the world’s energy is obtained from non-renewable resources like coal and petroleum, which are used for industries, homes and vehicles.

4. Renewable resources can naturally regenerate themselves, whereas nonrenewable resources cannot, which is how these two types of resources vary from one another.

Exhaustible and inexhaustible?

Answer: 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:

(i) Solar energy is free, making the operating cost of a solar cooker extremely low.

(ii) It is eco-friendly and does not produce any pollution.

(iii) It preserves nutrients in food as it cooks at moderate temperatures.

Disadvantages:

(i) The initial manufacturing cost of a solar cooker is relatively high.

(ii) It depends on sunlight, so it cannot be used at night or on cloudy days.

(iii) 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:

(a) Judicious Use of Fossil Fuels: Fossil fuels should be used sparingly and efficiently to maximize their benefits while minimizing their harmful effects.

(b) Adoption of Energy-Efficient Devices: Using energy-saving appliances such as LED bulbs, energy-efficient fans, and pressure cookers can significantly reduce energy wastage.

(c) 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.

(d) 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.

(e) 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.

(f) 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.