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Kinjal ray
Kinjal ray
@kinjal-ray
Noble Member
Joined: Nov 6, 2020
Last seen: Sep 30, 2021
Topics: 0 / Replies: 2124
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Answer to: Energy from various sources is considered to have been derived from the sun. Do you agree? Justify your answer.

Yes, sun is the ultimate source of energy. Directly or indirectly, all the forms of energy are derived from solar energy. Fossil fuels like coal, petr...

5 years ago
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Answer to: What are the environmental consequences of using fossil fuels? Suggest the steps to minimise the pollution caused by various sources of energy including non-conventional sources of energy.

Environmental consequences of using fossil fuels are: (i) They are the largest emitters of greenhouse gases such as carbon dioxide and methane. ...

5 years ago
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Answer to: Write two different ways of harnessing energy from ocean.

Ocean thermal energy and tidal energy can be harnessed from ocean.

5 years ago
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Answer to: Why is there a need to harness non-conventional sources of energy? Give two main reasons.

There is a need to harness non-conventional sources of energy because: (i) fossil fuels are limited sources and are depleting fast. (ii) burning...

5 years ago
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Answer to: Describe how hydro energy can be converted into electrical energy. Write any two limitations of hydro energy.

Conversion of hydro energy into electrical energy High rise dams are constructed on the river to obstruct the flow of water to collect it at a sui...

5 years ago
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Answer to: How are the wastes produced in nuclear power plants different from those produced in a thermal power plants ? What happens to the waste of a nuclear power plant?

The waste obtained from nuclear power plants is highly radioactive in nature which emits harmful radiations, whereas waste produced in a thermal power...

5 years ago
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Answer to: Name four gases commonly present in biogas. State two advantages of using this gas over fossil fuels.

Methane, carbon dioxide, hydrogen and hydrogen sulphide. Advantages of using biogas over fossil fuels are: Biogas burns without smoke, leaves no...

5 years ago
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Answer to: What happens when wood is burnt in a limited supply of oxygen? Name the residue left behind after the reaction and state two advantages of using this residue as a fuel over wood.

When wood is burnt in a limited supply of oxygen, volatile materials present in it get removed and cooled to get wood tar and wood gas. The black re...

5 years ago
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Answer to: Mention any four limitations in harnessing wind energy on a large scale.

Limitations in harnessing wind energy are: Speed of wind is not available at all time and at all places. To establish the wind energy farm, a lar...

5 years ago
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Answer to: (a) How does construction of dams across the river get linked with production of greenhouse gases? (b) How do technological inputs improve the efficiency of biomass fuels?

(a) A vast variety of plants get submerged in water, rot under anaerobic conditions and produce large amount of greenhouse gases such as methane. (...

5 years ago
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Answer to: (a) What is geothermal energy? (b) What are the advantages of wind energy?

(a) The heat energy obtained from the molten rocks formed in the deeper hot regions inside the earth are called geothermal energy. (b) Advantages of...

5 years ago
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Answer to: (a) Charcoal is a better fuel than wood. Why? (b) How does biogas plant help to reduce the problem of pollution?

(a) Charcoal is considered to be a better fuel than wood because: It burns without flames. It is comparatively smokeless. It has higher calorifi...

5 years ago
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Answer to: List any three hazards of nuclear waste. How does the disposal of nuclear waste pose a problem for the plant and animal life?

Hazards of nuclear wastes are: (i) Nuclear waste contains radioactive substances which emit harmful nuclear radiations. (ii) There is a high risk ...

5 years ago
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Answer to: Out of two solar cookers, one was covered with a plane glass slab and the other was left open. Which of the two solar cookers will be more efficient and why?

The solar cooker which was covered with a plane glass slab would be more efficient. The glass lid allows the heat radiation from sun to enter the sola...

5 years ago
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Answer to: What is a solar cell panel? Mention any three of its applications.

A large number of solar cells combined in an arrangement to obtain large electrical power is called solar cell panel. Applications of solar cell pan...

5 years ago
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Answer to: What are the advantages of nuclear energy?

Advantages of nuclear energy are: (i) A small quantity of nuclear fuel is needed to produce a large amount of useful energy. (ii) Nuclear power ...

5 years ago
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Answer to: Biogas is considered to be a boon to the farmers. Give reasons.

(i) It is the source of excellent manure, rich in nitrogen and phosphorous which can be obtained from the biogas plant in addition to biogas. (ii) ...

5 years ago
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Answer to: List two practical uses of biogas in rural areas.

Practical uses of biogas in rural area are: (i) It is an excellent fuel which burns without smoke with high heating capacity. (ii) It is also used...

5 years ago
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Answer to: Biogas is also known as gobar gas. Justify.

Starting material for biogas is mainly cow dung. So, it is also known as gobar gas.

5 years ago
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