1. Justify by giving two points that use of hydropower should be increased rather than that of coal and mineral oil for energy.
2. Hydropower is environment friendly but coal and oil destroy the environment. Hydropower is a renewable source of energy but coal and oil are non-renewable source of energy. Hydropower takes a short period of time to produce but coal and oil take millions of year to produce.
3. "The world will face an energy crisis in the near future." Justify this statement.
4. The world will face energy crisis in near future. This statement is justified by below mentioned points:
   
   1. Over dependency on non-renewable sources of energy.
   2. Non-renewable source of energy are limited in nature.
   3. Increasing population.
   4. Unsustainable urbanization and industrialization.
5. Write any two differences between fossil fuel and bio fuel.
6. Any two differences between fossil fuel and bio fuel are shown below in table:

   Fossil fuel	Bio fuel
   It can be obtained from the remains of dead animals and plants which were buried under the earth.	It can be obtained from different parts of plants and animal dung.
   It takes millions of years to form.	It is achieved in a short period of time.

7. Large amount of energy is produced during the fission of uranium atom. Give reason.
8. When uranium atoms break down, tiny new atoms are produced. Some mass is destroyed in this process. Infinite power is generated from that destroyed mass.
9. Gobar gas is more beneficial in rural area of Nepal. Give two reasons.
10. Gobar gas is more beneficial in rural area of Nepal because of the following points:
    1. It is available locally.
    2. It causes low pollution.
    3. It helps in forest conservation.
11. Government is giving high priority for solar energy. Why?
12. Government is giving high priority for solar energy because to decrease the dependency on non-renewable sources of energy and it does not pollute environment.
13. Energy crisis cannot be solved immediately but it can be pushed up to the next generation. Give reason.
14. The effort done for solution has become so late because the maximum number of non-renewable sources of energy stored in the earth has already been used up. The alternative sources of energy developed till now cannot held the energy demand in the short interval of time. It takes many years to regenerate the new sources.
15. In the present world, hydroelectricity is increasing. Write any two reasons.
16. In the present world, hydroelectricity is increasing because of the following reason:
    
    1. It is environment friendly.
    2. It is renewable source of energy and takes short period of time to produce.
17. Why is the use of wood as a fuel not advised although forests can be replenished?
18. The use of wood as a fuel not advised although forests can be replenished because of the following reasons:
    
    1. It cause air pollution.
    2. Negative impact on the ecosystem.
19. Government of Nepal encourages the farmers to establish bio-plant. Write any two reason.
20. Government of Nepal encourages the farmers to establish bio-plant because Nepal is agricultural country. Almost 90% people are engaged in agriculture and bio gas is also the product of agricultural matter.
    1. Bio gas is renewable source of energy and cheap.
    2. It is easy to make and its byproduct can be used as fertilizer.
    3. Raw material for the production of bio-gas are easily available.
21. Suggest three reasons which will help to solve the problem of energy crisis. Name three alternate sources of energy that are suitable for Nepal.
22. Three reasons which will help to solve the problem of energy crisis are listed below:
    1. Using bio gas plant to cook food.
    2. Wise and economic use of hydroelectricity.
    3. Using alternative source of energy to minimize the scarcity of nonrenewable source of energy.
    Three alternate sources of energy that are suitable for Nepal are: wind energy, bio mass energy, hydropower.
23. Write any two advantage of mineral oil.
24. Two advantage of mineral oil are listed below:
    1. It is relatively cheaper than other energy sources.
    2. It can be easily transported from one place to another.
25. Sun is also called atomic power plant, why?
26. In the sun, enormous energy is produced continuously due to nuclear fusion reaction as in the atomic power plant in nuclear station. Therefore, sun is also called atomic power plant.
27. Write any two reason that urbanization brings energy crisis.
28. Two reason that urbanization brings energy crisis are listed below:
    
    1. Consumption of nonrenewable source of energy has been increased with rapid population growth.
    2. The use of means of transportation has been increased that consequently consumed more mineral oil.
29. Why should energy be conserved? Write any two method to conserve at home.
30. Energy should be conserved to protect us from energy crisis in future which can bring many troubles because it is very essential in our daily life.
    Two method to conserve at home are:
    1. By using electricity wisely and economically, turn off the switches of TV, fan, bulbs if they are not in use.
    2. Using bio gas to cook food.
31. In the context of Nepal both bio-fuel and solar energy are useful. Out of these two sources of energy, which one will be more useful?
32. In the context of Nepal both bio-fuel and solar energy are useful but among them bio-fuel is more useful because of the following reason:
    1. Nepal is agricultural country, people can produce bio-fuel easily from the waste products of vegetables, animal dung from their own house.
    2. Bio-fuel is very easy and cheap to produce and its byproduct can be used as fertilizer.
33. What is main cause of energy crisis in Nepal? Write any one measure to solve it.
34. Main cause of energy crisis in Nepal are population growth, unsustainable urbanization and industrialization.
    Using alternative source of energy is the measure to solve it.
35. In the context of Nepal, use of solar energy should be highly prioritize, why?
36. In the context of Nepal, use of solar energy should be highly prioritize because it is never finished. It is environment friendly.
37. In future, the hydroelectricity will be main alternative source of energy for Nepal. Justify it with two reasons.
38. In future, the hydroelectricity will be main alternative source of energy for Nepal because of the following reasons:
    1. There are 3 permanent rovers and more than 6000 fast flowing rivulets in Nepal. They flow from high to low land and have enough kinetic energy.
    2. It is environment friendly and is renewable source of energy.
39. For what two natural process is the solar energy being used?
40. Solar energy is being used in photosynthesis and to maintain water cycle in Earth.
41. Fossil fuel energy is also a form of solar energy, how?
42. Plants make their food by photosynthesis which is the process with the help of solar energy. Animals eat plants and thus sun's energy is indirectly stored in animal. The plants and animals which get buried under the earth millions of years ago were converted into fossil fuel So, fossil fuel is a form of solar energy.
43. Hydroelectricity is an indirect source of solar energy. Clarify this statement.
44. The electricity which is produced from the water power is known as hydroelectricity. As we know, solar energy helps to maintain water cycler. Without sun we could not have water. So, hydroelectricity is an indirect source of solar energy.
45. It is difficult to produce hydroelectricity in Nepal. Give any two reasons.
46. It is difficult to produce hydroelectricity in Nepal because of the following reasons:
    1. Though there are many rivers and rivulets, there is lack of technology in Nepal to produce hydroelectricity conveniently.
    2. There is lack of skilled manpower.
    3. There is corruption and no political stability. No proper policy is made by government and rules and regulations are not implemented efficiently.