Last updated on February 9th, 2024 at 04:32 pm
CG Board Class 8 Science Sources of Energy Textbook Exercises which includes Fill in the blanks ,Question Answers and Extra Question and Answers from the Chapter.
Choose the correct alternative :-
(1) Out of these, this is a non renewable source of energy –
(a) Wind energy
(b) Petroleum [answer]
(c) Tidal energy
(d) Solar energy
(2) The fuel used in heavy vehicles as buses & trucks are –
(a) Tarpene
(b) Biogas
(c) Diesel [answer]
(d) Kerosene
(3) The energy converters in a solar cell is made of –
(a) Aluminium
(b) Carbon
(c) Plastic
(d) Silicon [answer]
(4) The energy received from the battery is :-
(a) Chemical energy
(b) Heat energy
(c) Electrical energy [answer]
(d) Mechanical energy
(5) It is not a product of petroleum :-
(a) Petrol
(b) Bio diesel [answer]
(c) Kerosene
(d) Diesel
Fill in the blanks :-
1. ………………. energy is mostly used in our homes.[Electrical]
2. Solar cooker is based on …………………. energy. [Solar]
3. Coal is a source of ………………….. energy. [Thermal]
4. Mixture of cowdung and water treated in special plant produce ………..[Biogas]
5. The liquid fuel in our homes is ……………………[LPG]
Match the following :-
| A | B |
| CNG | Natural gas |
| Sea | Tidal energy |
| Solar cooker | Solar energy |
| Wind Farm | Wind energy |
| Dams | Electrical Energy |
Answer the following questions in 3-4 lines :-
Q: Write names of four sources of energy.
Four sources of energy are:
a. Solar energy
b. Wind energy
c. Hydroelectric energy
d. Fossil fuels (e.g., coal, petroleum)
Q: What are the benefits of solar energy? Give two examples of its use in daily life.
A: Benefits of solar energy include being renewable, environmentally friendly, and cost-effective in the long run. Two examples of its use in daily life are solar panels on rooftops for electricity generation and solar water heaters for heating water.
Q: How is hydroelectricity produced? In Chhattisgarh where are the projects for hydroelectricty situated?
A: Hydroelectricity is produced by the force of flowing water turning turbines connected to generators. In Chhattisgarh, hydroelectricity projects are situated at Hasdev Bango and Gangrel dam projects.
Q: Write the names of the different products of petroleum.
A: Different products of petroleum include petrol (gasoline), diesel, kerosene, and petroleum gas (LPG).
Q: What is Biogas ? How is it produced?
A: Biogas is a mixture of gases, mainly methane and carbon dioxide, produced through the anaerobic decomposition of organic material like cow dung.
Q: List down the various sources of energy used in your surrounding and categorize them as renewable and non-renewable sources of energy ?
A: Various sources of energy used in the surroundings can be :
Renewable sources: Solar energy, wind energy, hydroelectric energy
Non-renewable sources: Fossil fuels (coal, petroleum)
Q: What are the main gases present in LPG?
A: The main gases present in LPG (Liquified Petroleum Gas) are butane, propane, and ethane.
Q: According to the available resources what kind of power station would you like to install in your area. Explain.
A: The choice of power station to install in the area will depend on the available resources, environmental impacts and energy requirements. If renewable resources such as wind or sunlight are in sufficient quantity, installing a wind or solar power station would be a sustainable option. The decision should be taken after considering local conditions and energy requirements.
CG Board Class 8 Science Sources of Energy Extra Question Answers
Q: How is electrical energy produced in dams?
A: Electrical energy in dams is produced by the force of flowing water turning turbines connected to generators.
Q: What do you understand by Tidal energy?
A: Tidal energy is the energy harnessed from the rise and fall of tides in the sea, usually by using dams and turbines.
Q: What is Nuclear energy?
A: Nuclear energy is produced through nuclear fission, where heavy atoms like uranium are split into smaller atoms, releasing a large amount of energy.
Q: What material is used in a Thermoelectric plant to produce electricity?
A: Thermoelectric plants use boilers to heat water by burning coal, which then produces steam to turn turbines and generate electricity.
Q: What are the main products of petroleum?
A: The main products of petroleum are petrol (gasoline), diesel, kerosene, and petroleum gas (LPG).
Q: What is the other name for cooking gas ? What are its constituents ?
A: Cooking gas is also known as LPG (Liquified Petroleum Gas) and mainly contains butane, along with propane and ethane.
Q: Bio-gas is a mixture of which gases?
A: Bio-gas is a mixture of gases, including methane and carbon dioxide, produced from the anaerobic decomposition of organic material like cow dung.
Q: Why is the solar cooker box painted black?
A: The solar cooker box is painted black to absorb and retain heat more effectively.
Q: In the solar water heater, energy is transformed into which form?
A: In a solar water heater, solar energy is transformed into heat energy.
Q: What is the solar cell made of?
A: Solar cells are made of silicon materials.
4. Why are the pipes of solar water heater made up of copper ?
A: The pipes of solar water heaters are made of copper because copper is a good conductor of heat and helps transfer the heat efficiently to the water.
Q: What can you do to conserve or save electrical energy in your homes?
A: To conserve electrical energy in your homes, you can use energy-efficient appliances, turn off lights and devices when not in use, and properly insulate your home.
Q: Biodiesel is obtained from which plant?
A: Biodiesel is obtained from the Ratanjot plant.
Q: In future, from which other sources can we obtain energy?
A: In the future, we can obtain energy from renewable sources such as wind, solar, and tidal energy to reduce dependence on non-renewable fossil fuels.
