Textbook Solutions: Towards Green Energy

 Page 1


Towards Green Energy 
Exercise 
Q. 1. Which fuel is used in thermal power plant? What are the problems 
associated with this type of power generation? 
Answer : Coal is used as fuel in thermal power plant. 
 
The problems associated with thermal power generation are: 
1. Air pollution – due to burning of coal, harmful gases like carbon di oxide, Sulphur 
oxide and nitrogen oxide is released which pollute the environment. 
2. Health problems – soot particles and the harmful gases like carbon dioxide, Sulphur 
oxide and nitrogen oxide released from burning coal may cause health issues related to 
respiratory system. 
3. Limited resources – coal is a non-renewable source of energy which means that the 
amount of coal present in earth is limited. Thus, there will be limitations in the usage of 
coal if not used cautiously and effectively now. 
Q. 2. Other than thermal power plant, which power plants use thermal energy for 
power generation? In what different ways is the thermal energy obtained? 
Answer : 1. Nuclear power plants: in nuclear power plants, the nuclear energy is 
obtained when uranium atoms are bombarded with neutrons. The uranium atoms break 
into smaller atoms through a process of fission, hence releasing nuclear energy. The 
nuclear energy obtained is converted into thermal energy. The kinetic energy of steam 
obtained through this is converted into kinetic energy of turbine which thus helps us 
obtain electrical energy. 
2. Solar thermal power plant: Thermal energy is obtained from solar radiation in solar 
thermal power plants. Many reflectors reflect and concentrate solar radiation on 
absorbers. There, the solar energy is converted into thermal energy. The thermal 
energy obtained from solar radiation is used to drive the turbine which thus helps in the 
generation of electricity in solar thermal power plants. 
Q. 3. Which type/types of power generation involve maximum number of steps of 
energy conversion? In which power generation is the number minimum? 
Answer : NUCLEAR POWER PLANT involves maximum number of steps in the 
process of transformation. 
 
1. First, nuclear energy is released by fission of nuclei of atoms like uranium or 
plutonium.2. The nuclear energy released is used to generate steam (thermal energy) of 
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Towards Green Energy 
Exercise 
Q. 1. Which fuel is used in thermal power plant? What are the problems 
associated with this type of power generation? 
Answer : Coal is used as fuel in thermal power plant. 
 
The problems associated with thermal power generation are: 
1. Air pollution – due to burning of coal, harmful gases like carbon di oxide, Sulphur 
oxide and nitrogen oxide is released which pollute the environment. 
2. Health problems – soot particles and the harmful gases like carbon dioxide, Sulphur 
oxide and nitrogen oxide released from burning coal may cause health issues related to 
respiratory system. 
3. Limited resources – coal is a non-renewable source of energy which means that the 
amount of coal present in earth is limited. Thus, there will be limitations in the usage of 
coal if not used cautiously and effectively now. 
Q. 2. Other than thermal power plant, which power plants use thermal energy for 
power generation? In what different ways is the thermal energy obtained? 
Answer : 1. Nuclear power plants: in nuclear power plants, the nuclear energy is 
obtained when uranium atoms are bombarded with neutrons. The uranium atoms break 
into smaller atoms through a process of fission, hence releasing nuclear energy. The 
nuclear energy obtained is converted into thermal energy. The kinetic energy of steam 
obtained through this is converted into kinetic energy of turbine which thus helps us 
obtain electrical energy. 
2. Solar thermal power plant: Thermal energy is obtained from solar radiation in solar 
thermal power plants. Many reflectors reflect and concentrate solar radiation on 
absorbers. There, the solar energy is converted into thermal energy. The thermal 
energy obtained from solar radiation is used to drive the turbine which thus helps in the 
generation of electricity in solar thermal power plants. 
Q. 3. Which type/types of power generation involve maximum number of steps of 
energy conversion? In which power generation is the number minimum? 
Answer : NUCLEAR POWER PLANT involves maximum number of steps in the 
process of transformation. 
 
1. First, nuclear energy is released by fission of nuclei of atoms like uranium or 
plutonium.2. The nuclear energy released is used to generate steam (thermal energy) of 
high temperature and high pressure.3. The thermal energy is transformed into kinetic 
energy in steam.4. The kinetic energy in steam, is then converted into kinetic energy in 
the turbine.5. The turbine rotates hence generating electrical energy. 
 
ELECTRIC GENERATOR USING WIND involves the minimum steps in the process of 
transformation. 
 
1. The kinetic energy in the wind is used in wind power plants2. This kinetic energy is 
converted to kinetic energy in the wind-turbine. Wind-turbine is a machine which 
converts the kinetic energy of the wind to electrical energy.3. The turbine rotates hence 
generating electrical energy. 
 
Q. 4. Solve the following crossword puzzle: 
 
a. Maximum energy generation in India is done using ..... Energy. 
b. ...... energy is a renewable source of energy 
c. Solar energy can be called.... energy. 
d. .... energy of wind is used in wind mills. 
e. ..... Energy of water in dams is used for generation of electricity. 
Answer : a. Maximum energy generation in India is done using thermal energy. 
Explanation: Thermal energy can be obtained using various fuels like water, nuclear 
compounds, solar energy. Thus thermal energy contributes to the maximum energy 
generation in india. 
b. Wind energy is a renewable source of energy. 
Explanation: There is a limitless supply of wind and wind energy is collected from 
sources which are replenished naturally. Thus, making wind energy a renewable source 
of energy. 
c. Solar energy can be called green energy. 
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Towards Green Energy 
Exercise 
Q. 1. Which fuel is used in thermal power plant? What are the problems 
associated with this type of power generation? 
Answer : Coal is used as fuel in thermal power plant. 
 
The problems associated with thermal power generation are: 
1. Air pollution – due to burning of coal, harmful gases like carbon di oxide, Sulphur 
oxide and nitrogen oxide is released which pollute the environment. 
2. Health problems – soot particles and the harmful gases like carbon dioxide, Sulphur 
oxide and nitrogen oxide released from burning coal may cause health issues related to 
respiratory system. 
3. Limited resources – coal is a non-renewable source of energy which means that the 
amount of coal present in earth is limited. Thus, there will be limitations in the usage of 
coal if not used cautiously and effectively now. 
Q. 2. Other than thermal power plant, which power plants use thermal energy for 
power generation? In what different ways is the thermal energy obtained? 
Answer : 1. Nuclear power plants: in nuclear power plants, the nuclear energy is 
obtained when uranium atoms are bombarded with neutrons. The uranium atoms break 
into smaller atoms through a process of fission, hence releasing nuclear energy. The 
nuclear energy obtained is converted into thermal energy. The kinetic energy of steam 
obtained through this is converted into kinetic energy of turbine which thus helps us 
obtain electrical energy. 
2. Solar thermal power plant: Thermal energy is obtained from solar radiation in solar 
thermal power plants. Many reflectors reflect and concentrate solar radiation on 
absorbers. There, the solar energy is converted into thermal energy. The thermal 
energy obtained from solar radiation is used to drive the turbine which thus helps in the 
generation of electricity in solar thermal power plants. 
Q. 3. Which type/types of power generation involve maximum number of steps of 
energy conversion? In which power generation is the number minimum? 
Answer : NUCLEAR POWER PLANT involves maximum number of steps in the 
process of transformation. 
 
1. First, nuclear energy is released by fission of nuclei of atoms like uranium or 
plutonium.2. The nuclear energy released is used to generate steam (thermal energy) of 
high temperature and high pressure.3. The thermal energy is transformed into kinetic 
energy in steam.4. The kinetic energy in steam, is then converted into kinetic energy in 
the turbine.5. The turbine rotates hence generating electrical energy. 
 
ELECTRIC GENERATOR USING WIND involves the minimum steps in the process of 
transformation. 
 
1. The kinetic energy in the wind is used in wind power plants2. This kinetic energy is 
converted to kinetic energy in the wind-turbine. Wind-turbine is a machine which 
converts the kinetic energy of the wind to electrical energy.3. The turbine rotates hence 
generating electrical energy. 
 
Q. 4. Solve the following crossword puzzle: 
 
a. Maximum energy generation in India is done using ..... Energy. 
b. ...... energy is a renewable source of energy 
c. Solar energy can be called.... energy. 
d. .... energy of wind is used in wind mills. 
e. ..... Energy of water in dams is used for generation of electricity. 
Answer : a. Maximum energy generation in India is done using thermal energy. 
Explanation: Thermal energy can be obtained using various fuels like water, nuclear 
compounds, solar energy. Thus thermal energy contributes to the maximum energy 
generation in india. 
b. Wind energy is a renewable source of energy. 
Explanation: There is a limitless supply of wind and wind energy is collected from 
sources which are replenished naturally. Thus, making wind energy a renewable source 
of energy. 
c. Solar energy can be called green energy. 
Explanation: Solar energy is obtained from sunlight, which is a renewable source of 
energy. Also, electricity obtained through solar energy does not cause any negative 
impact on the environment. Solar energy is an environmental friendly form of energy 
and is thus called green energy. 
d. Kinetic energy of wind is used in wind mills. 
Explanation: The kinetic energy in the wind is used in wind power plants. 
This kinetic energy is converted to kinetic energy in the wind-turbine, which rotates and 
produces electricity. 
e. Potential energy of water in dams is used for generation of electricity. 
Explanation: The potential energy in water stored in dam is converted into kinetic 
energy of water which drives the turbine, hence generating electrical energy. 
 
Q. 5. A. Explain the difference: 
 
Conventional and Non-conventional Sources of energy. 
Answer : 
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Towards Green Energy 
Exercise 
Q. 1. Which fuel is used in thermal power plant? What are the problems 
associated with this type of power generation? 
Answer : Coal is used as fuel in thermal power plant. 
 
The problems associated with thermal power generation are: 
1. Air pollution – due to burning of coal, harmful gases like carbon di oxide, Sulphur 
oxide and nitrogen oxide is released which pollute the environment. 
2. Health problems – soot particles and the harmful gases like carbon dioxide, Sulphur 
oxide and nitrogen oxide released from burning coal may cause health issues related to 
respiratory system. 
3. Limited resources – coal is a non-renewable source of energy which means that the 
amount of coal present in earth is limited. Thus, there will be limitations in the usage of 
coal if not used cautiously and effectively now. 
Q. 2. Other than thermal power plant, which power plants use thermal energy for 
power generation? In what different ways is the thermal energy obtained? 
Answer : 1. Nuclear power plants: in nuclear power plants, the nuclear energy is 
obtained when uranium atoms are bombarded with neutrons. The uranium atoms break 
into smaller atoms through a process of fission, hence releasing nuclear energy. The 
nuclear energy obtained is converted into thermal energy. The kinetic energy of steam 
obtained through this is converted into kinetic energy of turbine which thus helps us 
obtain electrical energy. 
2. Solar thermal power plant: Thermal energy is obtained from solar radiation in solar 
thermal power plants. Many reflectors reflect and concentrate solar radiation on 
absorbers. There, the solar energy is converted into thermal energy. The thermal 
energy obtained from solar radiation is used to drive the turbine which thus helps in the 
generation of electricity in solar thermal power plants. 
Q. 3. Which type/types of power generation involve maximum number of steps of 
energy conversion? In which power generation is the number minimum? 
Answer : NUCLEAR POWER PLANT involves maximum number of steps in the 
process of transformation. 
 
1. First, nuclear energy is released by fission of nuclei of atoms like uranium or 
plutonium.2. The nuclear energy released is used to generate steam (thermal energy) of 
high temperature and high pressure.3. The thermal energy is transformed into kinetic 
energy in steam.4. The kinetic energy in steam, is then converted into kinetic energy in 
the turbine.5. The turbine rotates hence generating electrical energy. 
 
ELECTRIC GENERATOR USING WIND involves the minimum steps in the process of 
transformation. 
 
1. The kinetic energy in the wind is used in wind power plants2. This kinetic energy is 
converted to kinetic energy in the wind-turbine. Wind-turbine is a machine which 
converts the kinetic energy of the wind to electrical energy.3. The turbine rotates hence 
generating electrical energy. 
 
Q. 4. Solve the following crossword puzzle: 
 
a. Maximum energy generation in India is done using ..... Energy. 
b. ...... energy is a renewable source of energy 
c. Solar energy can be called.... energy. 
d. .... energy of wind is used in wind mills. 
e. ..... Energy of water in dams is used for generation of electricity. 
Answer : a. Maximum energy generation in India is done using thermal energy. 
Explanation: Thermal energy can be obtained using various fuels like water, nuclear 
compounds, solar energy. Thus thermal energy contributes to the maximum energy 
generation in india. 
b. Wind energy is a renewable source of energy. 
Explanation: There is a limitless supply of wind and wind energy is collected from 
sources which are replenished naturally. Thus, making wind energy a renewable source 
of energy. 
c. Solar energy can be called green energy. 
Explanation: Solar energy is obtained from sunlight, which is a renewable source of 
energy. Also, electricity obtained through solar energy does not cause any negative 
impact on the environment. Solar energy is an environmental friendly form of energy 
and is thus called green energy. 
d. Kinetic energy of wind is used in wind mills. 
Explanation: The kinetic energy in the wind is used in wind power plants. 
This kinetic energy is converted to kinetic energy in the wind-turbine, which rotates and 
produces electricity. 
e. Potential energy of water in dams is used for generation of electricity. 
Explanation: The potential energy in water stored in dam is converted into kinetic 
energy of water which drives the turbine, hence generating electrical energy. 
 
Q. 5. A. Explain the difference: 
 
Conventional and Non-conventional Sources of energy. 
Answer : 
 
Q. 5. B. Explain the difference: 
 
Thermal electricity generation and solar thermal electricity generation. 
Answer : Thermal energy – 
1. Coal and nuclear fuel is used to generate electricity. 
2. The thermal energy released due to burning of fuel produces steam at very high 
temperature and pressure. This energy in the steam drives the turbine. 
 
Solar thermal electricity generation: 
1. The electricity is generated from solar radiations. 
2. Reflectors reflect and concentrate solar radiation on absorbers. The solar energy is 
converted into heat energy, which is used to drive the turbine and generator hence 
producing electricity. 
3. 
 
Page 5


Towards Green Energy 
Exercise 
Q. 1. Which fuel is used in thermal power plant? What are the problems 
associated with this type of power generation? 
Answer : Coal is used as fuel in thermal power plant. 
 
The problems associated with thermal power generation are: 
1. Air pollution – due to burning of coal, harmful gases like carbon di oxide, Sulphur 
oxide and nitrogen oxide is released which pollute the environment. 
2. Health problems – soot particles and the harmful gases like carbon dioxide, Sulphur 
oxide and nitrogen oxide released from burning coal may cause health issues related to 
respiratory system. 
3. Limited resources – coal is a non-renewable source of energy which means that the 
amount of coal present in earth is limited. Thus, there will be limitations in the usage of 
coal if not used cautiously and effectively now. 
Q. 2. Other than thermal power plant, which power plants use thermal energy for 
power generation? In what different ways is the thermal energy obtained? 
Answer : 1. Nuclear power plants: in nuclear power plants, the nuclear energy is 
obtained when uranium atoms are bombarded with neutrons. The uranium atoms break 
into smaller atoms through a process of fission, hence releasing nuclear energy. The 
nuclear energy obtained is converted into thermal energy. The kinetic energy of steam 
obtained through this is converted into kinetic energy of turbine which thus helps us 
obtain electrical energy. 
2. Solar thermal power plant: Thermal energy is obtained from solar radiation in solar 
thermal power plants. Many reflectors reflect and concentrate solar radiation on 
absorbers. There, the solar energy is converted into thermal energy. The thermal 
energy obtained from solar radiation is used to drive the turbine which thus helps in the 
generation of electricity in solar thermal power plants. 
Q. 3. Which type/types of power generation involve maximum number of steps of 
energy conversion? In which power generation is the number minimum? 
Answer : NUCLEAR POWER PLANT involves maximum number of steps in the 
process of transformation. 
 
1. First, nuclear energy is released by fission of nuclei of atoms like uranium or 
plutonium.2. The nuclear energy released is used to generate steam (thermal energy) of 
high temperature and high pressure.3. The thermal energy is transformed into kinetic 
energy in steam.4. The kinetic energy in steam, is then converted into kinetic energy in 
the turbine.5. The turbine rotates hence generating electrical energy. 
 
ELECTRIC GENERATOR USING WIND involves the minimum steps in the process of 
transformation. 
 
1. The kinetic energy in the wind is used in wind power plants2. This kinetic energy is 
converted to kinetic energy in the wind-turbine. Wind-turbine is a machine which 
converts the kinetic energy of the wind to electrical energy.3. The turbine rotates hence 
generating electrical energy. 
 
Q. 4. Solve the following crossword puzzle: 
 
a. Maximum energy generation in India is done using ..... Energy. 
b. ...... energy is a renewable source of energy 
c. Solar energy can be called.... energy. 
d. .... energy of wind is used in wind mills. 
e. ..... Energy of water in dams is used for generation of electricity. 
Answer : a. Maximum energy generation in India is done using thermal energy. 
Explanation: Thermal energy can be obtained using various fuels like water, nuclear 
compounds, solar energy. Thus thermal energy contributes to the maximum energy 
generation in india. 
b. Wind energy is a renewable source of energy. 
Explanation: There is a limitless supply of wind and wind energy is collected from 
sources which are replenished naturally. Thus, making wind energy a renewable source 
of energy. 
c. Solar energy can be called green energy. 
Explanation: Solar energy is obtained from sunlight, which is a renewable source of 
energy. Also, electricity obtained through solar energy does not cause any negative 
impact on the environment. Solar energy is an environmental friendly form of energy 
and is thus called green energy. 
d. Kinetic energy of wind is used in wind mills. 
Explanation: The kinetic energy in the wind is used in wind power plants. 
This kinetic energy is converted to kinetic energy in the wind-turbine, which rotates and 
produces electricity. 
e. Potential energy of water in dams is used for generation of electricity. 
Explanation: The potential energy in water stored in dam is converted into kinetic 
energy of water which drives the turbine, hence generating electrical energy. 
 
Q. 5. A. Explain the difference: 
 
Conventional and Non-conventional Sources of energy. 
Answer : 
 
Q. 5. B. Explain the difference: 
 
Thermal electricity generation and solar thermal electricity generation. 
Answer : Thermal energy – 
1. Coal and nuclear fuel is used to generate electricity. 
2. The thermal energy released due to burning of fuel produces steam at very high 
temperature and pressure. This energy in the steam drives the turbine. 
 
Solar thermal electricity generation: 
1. The electricity is generated from solar radiations. 
2. Reflectors reflect and concentrate solar radiation on absorbers. The solar energy is 
converted into heat energy, which is used to drive the turbine and generator hence 
producing electricity. 
3. 
 
Q. 6. What is meant by green energy? Which energy sources can be called as 
green energy sources and why? Give examples. 
Answer : i. Electricity made from renewable sources of energy is called green energy. 
ii. Green energy is environmental friendly as it does not contribute to depletion of 
environment. 
iii. Green energy can be obtained from sources like wind, tides, sunlight etc. these are 
called green energy sources. 
iv. These are called so, because they are ecofriendly sources of energy which do not 
cause pollution. 
v. Energy sources used are renewable and inexhaustible, which means that they are 
naturally replenished in nature over a period of time. 
Q. 7. A. Explain the following sentences 
 
Energy obtained from fossil fuels is not green energy. 
Answer : 1. Green energy is environmental friendly energy which does not contribute in 
degrading the environment. Some examples of green energy sources are wind, sunlight 
etc. while some examples of fossil fuels are coal, petroleum, natural gas etc. 
2. Electricity generation based on fossil fuels like coal, natural gas and nuclear fuels are 
not environment friendly. Electrical energy generated using these fuels can lead to 
degradation of the environment. 
3. Burning of fossil fuels lead to the emission of toxic gases and soot particles which mix 
in air causing air pollution and other respiratory diseases. 
4. It took millions of years for the formation of these sources. The amount of these fuel 
available is limited and thus must be used wisely and should not be wasted. 
5. Using nuclear fuels, can cause problems regarding the disposal of waste and the 
possibilities of disasters due to accidents. 
According to these facts, the energy generation from fossil fuels is not environment 
friendly. 
Q. 7. B. Explain the following sentences 
 
Saving energy is the need of the hour.