Solution of Chapter 14. Source of Energy (All In One Science Book)

What are the two characteristics of a good source of energy?

When do you say that a source of energy in non-renewable?

What is the difference between petroleum gas natural gas?

What are a conventional sources of energy?

Why should we avoid the use of fossil fuels as sources of energy?

Write any two points about good source of energy?

According to pie-chart which of the fossil fuel is most widely used in India?

Write two disadvantages of burning fossil fuels.

Write anyone way in which a thermal power plant differs from a hydro power plant.

What are the two negative impacts of a hydro power plant on the ecosystem?

What are the popular biomass used in India?

What is the composition of bio-gas?

Why bio-gas is also known as gobar-gas?

How does bio-gas plant help to reduce the problem of pollution?

What are the two limitations of harnessing wind energy?

Why is solar energy considered renewable?

Which element is used to make solar cells?

Why is the solar cooker box covered with a glass sheet?

A solar cell transforms energy from one form into another form. What are these two forms of energy?

What is a solar panel?

What are the different forms of energy available in ocean?

State one difference between tidal and wind energy.

What is nuclear fission?

What is nuclear fusion?

What are the disadvantages of using nuclear power?

Justify in one sentence that hydro power (hydro electricity) is a renewable source of energy.

Name any two devices used to harness solar energy.

In parabolic reflector type cookers, even temperature up to 1800^oC-2000^o can be attained. How?

What type of energy transformation takes place during winding of spring of a clock?

In many applications, solar cells are connected to rechargeable batteries. Why is it so?

How is the increase in demand for energy affecting our environment adversely?

How were fossil fuel formed?

Name four gases commonly present in biogas. State two advantages of using this gas over fossil fuels.

Of the major requirement of different forms of energies, write which one is the greater requirement of India and which is the least? What is the percentage of the hydro energy requirement of India?

For producing electricity, the energy from flowing water is preferred to energy obtained by burning coke. State two reasons for it.

Give a few examples of how our ancestors used the energy possessed by the wind and water.

Out of two solar cookers, one was covered by a plane glass slab and the other was left open. Which of the two solar cookers will be more efficient and why?

people living on hills often get sunburns on their skin. Which component of sunlight is responsible for this effect? Why is this effect generally not observed near sea level?

A certain form of energy which is not sourced directly or indirectly from the sun and does not cause any pollution is very easily converted into electricity. This form of energy is however, not available everywhere. Moreover, it is technically very difficult and expensive to obtain it. Name the form of energy.

Why any source of energy has less consequence? Explain your answer with suitable example.

what is the cause of release of unusually large energies in nuclear fission reactions? How is the energy per fission calculated?

The solar constant at a place is 1.4 kW/m². How much will solar energy be received at this place per second over an area of 5 m²?

What is the basic cause for winds to blow? Name a part of India, where wind energy is commercially harnessed. Compare wind power and power of water flow in respect of generating mechanical and electrical energies. What is the hindrance in developing them?

A certain form of energy is available due to the difference in the temperature of water at the surface of the ocean and its deeper levels.

(i) Name the form of energy.

(ii) Is this energy ultimately derived from the sun or not?

(iii) Explain, how this form of energy can be converted into electricity?

Nikhil and Neha went to a remote village in Kerala to meet their grandmother. They were surprised to see bio-gas plant in Mr. Nair’s house in the neighborhood. There was plenty of livestock and the house hold use cooking gas from the plant. Also, their farm had rich vegetation. They contacted sarpanch of the village and convinced him to set up a bio-gas plant for village community.

(i) Mention the values displayed by Mr. Nair. Nikhil and Neha.

(ii) Explain the possible arguments given by Nikhil and Neha to the sarpanch to convince him to set up a bio-gas plant.

Hemant visited his neighboring village, where a bio-gas plant has been installed recently. He was surprised to see the working of the bio-gas plant. He told his village elders about the advantages of setting up a bio-gas plant in their village. Now. Answer the following question:

(i) What are the advantages of a biogas plant?

(ii) Why is a bio-gas plant commonly called as gobar gas plant?

(iii) Why were the villagers are very much impressed with Hemant?

When the material P mined from the earth is heated strongly in an insufficient supply of air, it produces a solid fuel Q which mainly consist of carbon. When another material R obtained from trees is heated in an insufficient supply of air, it produces another solid fuel S which also consists mainly of carbon. Then, which of the following is true?

100 W/m² of solar energy is received by the Earth. If all the energy was to be absorbed by a bucket of water (mass 30 kg) in 30 minutes, then the rise in temperature of water will be

While filling LPG in cylinders, a substance X is added to make the detection of leakage of LPG from the cylinder easy. The substance X is

For a nuclear reactor, 48 kJ of energy is produced per minute. If the energy released per fission is 3.2 × 10^-11 J, then the number of fission which would be taking place in a reactor per second is

The mass number of four different elements A, B, C and D are 2, 35, 135 and 239, respectively. Which of them would provide the most suitable the most suitable for nuclear fission?