1.Identify the Inexhaustible sources of energy 1 point a) Coal b) Pertol c) CNG d) Solar enregy
Answers
Answer:
- The Inexhaustible sources of energy is d) Solar enregy.
Explanation:
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Answer:
1. What is a good source of energy?
Ans. The energy which is easily available, cheap, does not produce pollution is said to be good source.
2. What is a good fuel?
Ans. A good fuel is one which is cheap, easily available, easy to handle, transport, has proper ignition temperature and high calorific value.
3. If you could use any source of energy for heating your food, which one would you. us? and why?
Ans. If sun�s ,heat is accessible then solar cooker or else CNG.
4. What are the disadvantages of fossil fuels?
Ans. Disadvantages of fossil fuels are:
(a) They are non-renewable resources
(b) They cause pollution which can lead to
(i) Acid rain
(ii) Smoke
(iii) Green house effect due to CO2
(iv) Fly ash suspended in air.
5. Why are we looking at alternate sources of energy?
Ans. The sources of energy we are using now is fossil fuel i.e., petrol and petroleum products, and coal which are exhaustible and non-renewable. The demand of energy is increasing due to increased population and better technology that has added many machines, appliances to add comfort to life style. Hence ,the. demand for energy is increasing day by day. To overcome this problem we are looking for alternate sources of energy.
6. How has the traditional use of wind and water energy been modified for our convenience?
Ans. (i) The traditional use of water energy has been modified and we have built dams, turbines and dynamos to generate electricity with the help of flow of water.
(ii) Wind; energy is used to rotate the wind mills, turbines and generate electricity by constructing wind fans.
7. What kind of mirror-concave, convex or plain-would be best suited for use in a solar cooker? Why?
Ans. Concave minor would be best suited for use in solar cooker. As it is a converging mirror and would converge sun�s heat radiation at one focussed point.
8. What are the limitations of the energy that can be obtained from the oceans?
Ans. The limitations of ocean energy are:
(i) Few limited sites/places where this wave, tidal or ocean thermal energy can be obtained.
(ii) The cost of construction of plants is very; high
(iii) The efficiency of producing energy is also low
9. What is geothermal energy?
Ans. The heat energy obtained in the form of steam from under the earth�s crust is called geothermal energy
10. What are the advantages of nuclear energy?
Ans. The advantages of nuclear energy are:
(i) A very small amount of radioactive material can produce large amount of energy which can be controlled and converted into usable form e.g., 1 kg Uranium = 25 thousand tonnes of coal.
(ii) It does not release any smoke or harmful gases in the air. Hence it can, curbthe global warming that is caused due to green house effect.
11. Can any source of energy be pollution free? Why or why not?
Ans. Yes, there can be a source of energy that can be pollution free in using it. e.g., sun�s energy that is used in solar cooker, solar water heater, solar cell panels.
12. Hydrogen has been used as a rocket fuel. Would you consider It a cleaner fuel than CNG? Why or why not?
Ans. Hydrogen is a cleaner fuel than CNG because hydrogen on burning/combustion form water whereas CNG that contain methane burns to produce carbon dioxide.
13. Name two energy sources that you would consider to be renewable. Give reasons fur your choices.
Ans. Solar energy-it will not get exhausted it can be used for multipurpose-heating, burning and producing electricity. It will not cause any pollution, it is cheap and easily available.
Energy from water-Energy can be obtained from water in various form i.e., for producing electricity without pollution