CG SCERT Chhattisgarh State Board Class 8 Science & Technology Chapter 12 Sources of Energy Exercises Questions and Answers.
1.) Choose the correct alternative
1.) Out of these ,this is a non renewable source of energy-
a) Wind energy
b) Petroleum
c) Tidal energy
d) Solar energy
Ans-b) petroleum
2.) The fuel used in heavy vehicles as buses and trucks are-
a) Tarpene
b) Biogas
c) Diesel
d) Kerosene
Ans-c) diesel
3.) The energy converts in a solar cell is made of-
a) Aluminium
b) Carbon
c) Plastic
d) Silicon
Ans-d) silicon
4.) The energy received from the battery is-
a) Chemical energy
b) Heat energy
c) Electrical energy
d) Mechanical energy
Ans- c) electrical energy
5.) It is not a product of petroleum-
a) Petrol
b) Bio diesel
c) Kerosene
d) Diesel
Ans-b)biodiesel
2.) Fill in the blanks
1.) —- energy is mostly used in our homes.
Ans- electrical or electricity
2.) Solar cooker is based on —– energy
Ans-solar energy
3.) Coal is a sources of —– energy
Ans- non- renewable
4.) Mixture of cowdung and water treated in special plant produce—- gas
Ans-bio- gas
5.) The liquid fuel in our homes is —–
Ans-vegetable oil
3.) Match the pairs.
- CNG- Natural Gas
- Sea- electrical energy
- Solar cooker- Solar energy
- Wind farm-wind energy
- Dams- Tidal energy
4.) Answer the following questions.
1.) Write names of four sources of energy.
Ans- a) solar energy
b) wind energy
c) tidal energy
d) electrical energy
2.) What are the benefits of solar energy? Give two examples of its use in daily life.
Ans-solar energy is the renewable source of energy therefore we use it. There is no any cost for this energy.
In our daily life we can use solar energy for heating water.
We can use the solar cookers, solar water heaters etc.
3.) How is hydroelectricity produced? In chhattisgrah where are the projects for hydroelectricity situated?
Ans- for the produces of hydroelectricity there is some arrangements in Dams, where the accumulated water is made to flow with a force such that the turbines on its way turn or rotate then this turbine is connected by a shaft to generators which produce electricity. In Chhattisgarh hydroelectricity is produced at Hasdev Bango and Gangrel dam.
4.) Write the names of the different products of petroleum .
Ans-Petrol, Diesel , Kerosene and petroleum gas are the products of petroleum.
5.) What is biogas ? how is it produced?
Ans- Bio- gas is a fuel and which is used for cooking gas. Bio- gas is produced from cowdung which is dissolved in water and put in specially prepared covered pits. In this pits mixture in the absence of air is reduced to form methane , carbondioxide and some other gases. therefore this mixture is of gases is known as Bio –gas.
6.) List down the various sources of energy used in your surroundings and categorize them as renewable and non-renewable sources of energy.
Ans- there are various sources of energy used in our surroundings like solar energy, wind energy, electrical energy, tidal energy, bio- gas , petroleum and coal are also used in our surroundings,
Renewable sources of energy are solar energy, wind energy, hydro energy, tidal energy are the renewable sources of energy
Non- Renewable source energy –wood ,coal, petroleum ,fossil fuels natural gas etc are the non renewable sources of energy.
7.) What are the main gases present in LPG?
Ans- LPG contains butane ,propane and ethane gases are the main gases present in LPG.
8.) According to the available resources what kind of power station would you like to install in your area.
Ans- I like to install solar power station in my area because solar energy does not have any cost and we use it for heating water, cooking food, and also we use it for other electrical instruments also so I like to install solar power station in our area.