Class 10 Science Chapter 14 Important Questions

Class 10 Science Chapter 14 Important Questions of Sources of Energy. All the questions are taken from NCERT Textbooks. These provides an extra practice to the students during the preparation of school exams as well as board exams. Class 10 Science Chapter 14 Extra Questions contains short and long questions with answers and explanation. UP Board students are also using NCERT for the academic session 2020-2021, these important extra questions are useful for UP board students also. Questions are divided into sets of 5 questions for the simplicity and to make study easier. Previous years CBSE board examination questions are also available with answers.

After going through NCERT Chapter 13 of 10th Science, student must see these questions to solve their doubts. Contact us, if you face any difficulty during the use of Tiwari Academy website or Tiwari Academy Apps.

Class 10 Science Chapter 14 Important Questions for Exams

Class: 10Science
Chapter: 14Important Extra Questions with Answers

Class 10 Science Chapter 14 Extra Questions 2020-21

Class 10 Science Chapter 14 Important Extra Questions with answers are given below. All the questions are solved with suitable answers. Class 10 Science Chapter 14 Extra questions contains most of the frequently asked questions in the school tests. Answers of these questions are confined to NCERT Books only.

10th Science Chapter 14 Important Questions Set – 1

What is meant by the source of energy?

We need energy to perform various function of life. The material that provide the requisite amount of energy is the source of energy. For example,
(i) We need heat energy too cook food. The various sources are: Fuels, wood, coal, kerosene, cooking gas etc.
(ii) We need energy for our transport. The various sources are: Petrol, diesel.
(iii) We need energy to light bulbs, tubes, to run radio, television and other power appliances. The source is electricity.
(iv) Production in factories and agriculture also need energy. The source is diesel and electricity.

List any four factor that should be taken into consideration in the choice of a good sources of energy.

The following are the characteristic of a good source of energy:
(i) It should give an adequate amount of net energy or work per unit volume of mass.
(ii) It must be convenient to use so as to give energy at a steady rate.
(iii) It must be easy to store and transport.
(iv) It must be economical.

What is meant by the transformation of energy? Explain giving an example.

The change of one form of energy into another form of energy is called transformation of energy. The different forms of energy are: potential energy, kinetic energy, chemical energy, heat energy, solar energy, electrical energy and light energy. When a body from a height falls to the ground its potential energy is convert into kinetic energy and then into heat energy.

Write two advantages of classifying energy sources as renewable and non-renewable.

Advantages of classifying energy as renewable or non-renewable are:
(i) It tells us which energy sources should be used judiciously that it could be used for maximum length of time example non-renewable sources.
(ii) It promotes to develop newer methods to use a particular source economically example renewable sources.

What is a fuel?

Any substance which may be burnt in air to produce heat and light is known as fuel. For example wood, coal, kerosene, petrol.

10th Science Chapter 14 Important Questions Set – 2

What are fossil fuels?

Coal, petroleum and natural gas are examples of fossils fuels. These are found in nature due to the decompose of animals and plants which have remained embedded inside earth crust due to geological changes over millions of years.

Explain why are fossil fuels classified as non-renewable source of energy?

Fossil fuels are obtained from the buried plants and animals processes. Thus chances of reoccurring of such processes is very rare and after the present stock is exhausted, we cannot hope to get new stocks unless there are drastic changes in the changes in the earth processes. So fossil fuels are classified as non-renewable sources.

State with reason three disadvantage of using fossil fuels?

(i) Burning of coal and petroleum lead to air pollution.
(ii) They cause acid rain by forming oxides of carbon, nitrogen and sulphur. This affects our water and soil sources.
(iii) Burning of fossil fuels cause smog which cause breathing problems and other hazards.

Why is the use of wood as a fuel not advised although forests can be replenished?

It takes more than 15 years for a tree to mature. Cutting of wood also causes environment imbalance. Further burning of wood causes a lot of pollution. For these reason it is not advised to use wood as a fuel.

Why should fossil fuel be used with caution?

It took millions of years for fossil fuels to be formed. So if all the fossil fuels are exhausted today, then it will be after another long period of millions of years that people can hope to see these again. So they should be used with care and caution and not wasted at all.

Non-renewable Resources

Fossil fuels like coal, petroleum and natural gas are non-renewable energy sources. These are produced over millions of years due to show changes and under special circumstances. These are not continuous processes and further it is not becoming possible to discover their new deposits. With the present rate of their consumption it is estimated that known deposits of petroleum in our country will be exhausted in another 200 years and that of coal may last for another 250 years.

10th Science Chapter 14 Important Questions Set – 3

What is bio-mass? Is it the conventional source of energy?

The material obtained from plants and animals used as fuel is called bio-mass. It is the conventional source of energy mainly in rural areas. For example, wood, agriculture, wastes and animal dung cakes together contribute about 80 per cent of the domestic requirement of fuel in rural areas.

State briefly the hazards of using conventional sources of energy?

Some of the conventional sources of energy have poor efficiency and produce a lot of smoke due to incomplete combustion. For example,
Wood: As well-known wood is burnt in traditional chulhas. It has poor efficiency because only about 8% of the wood is utilised as fuel. Besides incomplete burning it produce gases like carbon monoxide which are dangerous for health. It also leaves a lot of ashes.
Animal dung: Animal dung mixed with mud and made in the form of cakes and dried are burnt in many parts of the country for use for domestic purposes. As crowding cakes are burnt inefficiently in the conventional manner, it produces a lot of smoke. Further as animal dung contains useful nutrients for soil, the burning of animal dung causes considerable wastage of useful elements, besides producing air pollution.
Agricultural wastage: Agricultural wastage like sugarcane are burnt for use in industries. This and other animal and plant wastes could more profitably be used in bio gas plants.

List any two steps you would suggest to minimise environmental pollution caused by burning of fossil fuels?

(i) The evolution of poisonous gases can be reduced by use of efficient combustion process and techniques.
(ii) Ashes etc. should be properly discarded.

Enumerate hazards of incomplete combustion.

Fuels contain a large amount of carbon. When combustion is incomplete most of the carbon gets converted into carbon monoxide. Also unburnt carbon passes into atmosphere. It causes the following problems:
1. Carbon monoxide is extremely poisonous and cause acute respiratory problem.
2. Carbon monoxide pollutes the atmosphere and damage ozone layer which saves us from ill-effect of ultraviolet rays.
3. Due of release of unburnt carbon vapours, atmosphere gets polluted and fuel is also wasted unnecessarily.

What are the two ways in which animal dung can be utilised as a fuel? Which of them is better.

There are two ways in which animal dung can be used as fuel:
(i) To heat animal dung in the form of cakes.
(ii) Anaerobic degradation of animal dung to produce useful fuel called bio-gas.
The second method gives fuel which is more efficient and thus it is a better way of using animal dung as a fuel.

10th Science Chapter 14 Important Questions Set – 4

Give the raw materials used for the preparation of bio-gas?

The following materials may be used to produce bio-gas:
(i) Plant wastes like husk, grass, dry leaves, weeds, vegetable strains.
(ii) Animal wastes like cow dung, dungs of horse, elephant, goat and poultry wastes.
(iii) Industrial and domestic wastes like mill dust, fruit and vegetable wastes.
(iv) Human excrete and faecal matter.

Explain how bio-mass is used as a fuel?

Animal and plant wastes are called bio mass. These are degraded by anaerobic organisms in the presence of water to form mixture of gases such as methane, carbon dioxide, hydrogen and hydrogen Sulphide. The mixture of gases is called bio-gas. Methane is an excellent fuel.

Give three reason why the use of cow dung in bio-gas plants is preferred to burning cow-dung cakes for cooking.

The use of cow dung in bio gas plants to produce bio gas as fuel is preferred over the use of cow dung directly because of the following reasons:

(i) Cow dung contains important nutrient like nitrogen and phosphorus, which are very useful for crops. Now when the cow dung is used to prepare bio-gas then the residue left behind is still rich in nutrient and can be used as manure. But if the cow dung is burnt in the form of dried cow-dung cakes, then the nutrient contained therein are destroyed and hence cannot be used as manure.

(ii) The fuel obtained by the use of cow dung in bio gas plants does not produce any smoke on burning and does not cause air pollution. On the other hand, cow dung cakes on burning produce a lot of smoke which cause air pollution.

(iii) The fuel obtained by the use of cow dung in bio gas plants is a clean fuel and does not leave behind any ash or residue. On the other hand, cow dung cakes doo not burn completely and leave behind a lot of ash.

Why is charcoal considered to be a better fuel than wood?

Charcoal is a better fuel than wood because it
(i) burns without flame
(ii) is comparatively smokeless
(iii) has higher heat generation efficiency.

What is bio gas? How is it obtained from plant or animal wastes?

Bio-gas is a mixture of methane, hydrogen, carbon dioxide and hydrogen Sulphide. Methane is the major constituent. It is also called gobar-gas. Animal wastes and plant wastes contain a lot of carbon compounds like carbohydrates, proteins and fats. The anaerobic bacteria in the presence of water but in the absence of air, degradation these compounds to methane gas which is the main constituent. Other gases like CO2, H2S, H2 are also formed.

Renewable Resources

The energy derived from flowering water, wind, tides, ocean waves and bio-gas are the renewable sources. These sources can be harnessed into energy so long as the earth derives its heat and light from the sun or so long as the present solar system exists. Nuclear energy and geothermal energy is also likely to be available for a much longer time. Wood is another renewable source of energy. Thought it takes almost 15 years for a tree to mature, this and nuclear energy are also classified as renewable sources.

10th Science Chapter 14 Important Questions Set – 5

Why is bio-gas considered an ideal fuel for domestic use?

Bio-gas is considered a good domestic fuel because of the following reasons:
(i) Bio-gas burns without any smoke and so does not cause air pollution.
(ii) Bio-gas produces a large amount of heat per unit mass and thus has high calorific value.
(iii) Bio-gas does not leave any residue on burning and is thus a clean fuel.
(iv) Bio-gas does not cause any storage problem. It can be continuously supplied by pipes directly from the gas plant.
(v) The produce of bio-gas does not involve any running cost and is cheaper than most common fuels.

What do you understand by the community gas plants?

Many village families neither have adequate number of cattle to feed the individual bio-gas plant nor do they have means to meet the initial cost for the construction of bio-gas plant is shared by plant their own. In such cases the cost of installing such a big bio-gas plant is shared by all the plant all the people in the village community and all and all the cattle dung available in the village is used to feed the common bio-gas plant. The bio-gas produced therein is supplied to all the village homes through gas pipes.

Suggest two materials that can be used to produce bio-gas. Mention two uses to bio-gas and two advantages of bio-gas plant.

Materials that can be used to produce bio-gas: cow dung, vegetable wastes.
Uses of bio-gas
(i) It can be used for cooking food and other domestic heating purposes.
(ii) It can be used for street lighting.
Advantages of bio-gas plant
(i) It provides useful manure for agriculture.
(ii) It controls water pollution by using sewage disposal.

What is meant by the Bio-mass? How does it can be preparing? How we can use it in different ways?

The residue of living organisms such as remains of plant, animal, and their products from which fuel can be obtained is called biomass. Biomass is a renewable source of energy.
It includes
(a) biodegradable material from industries
(b) organic waste material
(c) agriculture and forest residues.

Bio-mass can be used
(a) as a bio-fuel
(b) for the production of fibre, paper, chemical or heat
(c) as a source of energy in industries
(d) to generate
(e) to produce biogas by its anaerobic digestion.

What is meant by the Wind energy? What are the factor responsible for the blowing wind? What causes the wind to blow? Explain some uses of wind energy.

The kinetic energy possessed by the blowing wind is called wind energy. The factors responsible for the blowing wind are: (i) Uneven heating of equational region and polar region of earth by sun rays.
(ii) Rotation of earth about its own axis.
(iii) Prevailing local condition in the region.
Equational region of earth receives of earth more solar heat radiations from the sun as compared to other parts of the earth. Therefore, the air in these regions warms and rises up the air in these regions warms and rises up. The cooler air from the polar regions starts. Blowing towards the equatorial hot region to fill the space vacated by the hot upward rising air. As a result, movement of air take place which forms the wind.
Uses of wind energy. The uses of wind energy are well known to mankind for centuries. The harnessing of wind energy can be done in the following ways:
(i) It is used to generate electricity.
(ii) It helps to propel glider, sail boats in the desired direction.
(iii) It rotates the blades of wind mill for pumping water or to run the flour mills.

10th Science Chapter 14 Important Questions Set – 6

What is meant by the solar energy? What do you understand by the harnessing of solar energy? Explain the uses of solar energy.

The enormous amount of energy radiated by the sun in all direction in the form of heat and light is called solar energy.
(a) It is the ultimate source of energy.
(b) Nuclear fusion of deuterium is the main cause which generates energy on the sun.
(c) Under clear sky conditions India receives solar energy solar energy from 4 to 7kWh/m2
Harnessing of solar energy: Solar energy can be harnessed directly or indirectly.
(a) Direct harnessing: Solar energy can be converted into electricity directly by the use of solar cells or its heat energy can be used solar cookers or solar water heater.
(b) Indirect harnessing: Solar energy is responsible for photosynthesis reaction in plants, movement of wind, ocean thermal energy, hydroelectricity and other forms due to difference in temperature at different levels are the various ways through which solar energy can be indirectly harnessed.
Uses of solar energy: Solar energy can be used:
(i) to generate electricity by using solar power plants.
(ii) to obtain salt from the sea water by evaporation.
(iii) to preserve sea plant sea food, vegetables and fruits for long time by using sun drying method.
(iv) to heat water, food and remove moisture content from the grains.
(v) Solar energy is used in watches and calculator.

What is meant by the solar cooker? How does it work?

The device which cooks the food without using any conventional cooking fuel and converts solar energy directly into heat energy is known as solar cooker.
(i) It works on the principle that black surface absorb more heat as compared to white or a reflecting surface under identical conditions.
(ii) It consist of a well metallic or wooden box which is painted dull black.
(iii) The collection of solar energy is done either by using a plane mirror or a large concave mirror which acts as a reflectors attached to one of the top edges of the box.
(iv) The top of the box exposed to the sun and covered by one or more transparent cover such as glass plate to trap the heat inside the box.
(v) Similar to greenhouse effect the glass lid allows the heat radiation from sun to enter inside but does not allow the reflected heat radiation to escape or go outside the box. This heat is absorbed by the blackened surface. Thus the heat loss is reduced due to reflection.
(vi) Temperature inside the box increases slowly and rises from 100 to 140 in two three hour on a clear sunny day.
(vii) This heat is utilised to cook the food. Thus solar cooker saves sustained amount of cooking fuel and contributes towards the economy of a family.

What do you understand by the Energy from the sea? Explain it three different forms.

The oceans cover about 70% of the earth surface area. They contain a lot of energy because water has a high specific heat capacity. Ocean acts as a renewable source of energy. The energy of ocean is available in different forms.
(i) Tidal energy: The energy produced by the surge of ocean water during high and low tides due to difference in sea levels is called tidal energy. The high and low tide occur due to gravitational pull of the moon. This cause enormous movement level of water. Tidal energy is harnessed by constructing a dam near the shores. During high tides water flows into the dam and during low tides, water flows out. This flowing water routes thee turbine, present at the opening of dam and produces electricity.
(ii) Sea-wave-energy.
The strong wind flowing across the sea generates waves in the sea.
Kinetic energy possessed by these sea waves can be used to generates electricity.
The harnessing sea wave energy would be viable position only where waves are so strong.
Technology is still in developing stage to get more efficient devices to traces sea wave energy.
These devices convert the wave energy into rotational motion of the shaft which is used to produce electricity with the help of an electric generator.
(iii) Ocean Thermal Energy Conversion
Water at the surface of an ocean or sea warms up by the solar energy while the deeper water remain cold.
The temperature difference surface water and water at a depth of 2km is approximately 20 C or more.
The energy available due to this temperature difference is called ocean thermal energy.
The ocean thermal energy can be utilise to run OCTEC plant.

Explain in brief about the geothermal energy.

The energy obtained from hot molten rocks and trapped hot fluid inside the earth is called geothermal energy.
It is not related directly or indirectly to the sun’s energy.
At some depth below the surface of earth the rocks get heated due to fission of radioactive materials present in it which liberates large amount of energy.
Due to geological changes these molten rocks in the interior of earth are pushed upward and trapped in certain regions. These regions are called hot spot.
The underground water which comes in contact with these hot spots gets heated and it converted into steam.
The steam trapped inside the rock at high pressure is taken out through a pipe to a turbine or generate electricity.
In some places hot water comes to the surface through some outlets. This outlets are called hot springs.

What are the merits of fusion?

Fusion process has merits over the fission process which are:
(i) Fusion products are non-radioactive and thus harmless.
(ii) Causes less pollution problems.
(iii) Gives more energy as compare to fission.
(iv) Fuels in the form of hydrogen is available in plenty.

Compare Bio Mass with Bio Gas

Bio MassBio Gas
1. It is produced too much smoke.1. It does not produce any harmful gas.
2. Its calorific value is low.2. Its calorific value is high.
3. Ash is left as residue.3. It does not leave any residue.
4. Organic matter gets destroyed.4. Organic matter is secured and is available for use as manure.

10th Science Chapter 14 Important Questions Set – 7

What is meant by the nuclear reactor and the energy obtained is utilised for what purpose?

The device where a self-sustaining chain reaction produced in a fissionable material such as uranium or plutonium that released energy in a controlled manner is called nuclear reactor.
The energy obtained is utilised for many useful purpose such as
(i) Electric power generation.
(ii) Propulsion of ships, submarines and air crafts.
(iii) neutron beam for treatment of cancer, nuclear research etc.

What are the major hazards and Limitation of nuclear power plant?

(i) Environmental contamination due to improper nuclear waste storage and its disposal.
(ii) High cost of installation
(iii) Limited availability of nuclear fuel.
(iv) Risk of accidental leakage of harmful radiation during processing of nuclear fuel or damage, if or damage, if any in nuclear reactor.
(v) Land become barren.

What are the steps to reduce the energy consumption?

(i) Avoid misuse of conventional sources of energy which are limited in nature.
(ii) Alternate source of energy such as solar energy, wind energy, hydro energy, etc., should be used instead of non-renewable source of energy.
(iii) Efficiency of energy sources should be repeatedly maintained for getting the maximum efficiency.
(iv) Research should be continued to produce long lasting alternate sources of energy devices so that the environmental damage caused by assembly of devices gets minimised.

Name one fuel used in nuclear reactor.

Uranium 235

Name any two elements that are used in fabricating solar cells.

Germanium, silicon

Conventional Sources of Energy

These are the sources of energy that we have often been using for a long time. For example, wood and fossil fuels like coal, petroleum have been common sources of heat energy. The energy of flowing water and wind are also used for limited activities.

Non-conventional Sources of Energy

With increasing demand recently energy from sun, sea waves and earth is also being tapped now a days. These derived energies are called non-conventional sources of energy.

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