TWO MARKS QUESTION
10. list two advantages and disadvantages each for using wind as a source of energy.
11. Write two differences between renewable and non-renewable sources of energy
12. What is the principle of solar cooker? Name two types of solar cooker.
13. Name any two types of harmful nuclear radiations emitted during nuclear mission
14. What is thermal power plant? Where it is preferably situated?
15. What is the use of black painted surface in solar heating devises.
16. Why are bio gas plants considered to be boon to the farmers? Give reason.
17. Hydroelectricity generated at a dam may be considered another form of solar en
18. Why is charcoal considered to be a better fuel than wood?
19. Why a solar cooker cannot be used for frying or making chapattis?
20. Hydrogen has been used as a rocket fuel. Would you consider it a cleaner fuelth
Why or why not?
21. Fire wood is our conventional fuel. List any four reasons of replacing it with
sources of energy.
Answers
Q10.ADVAVTAGES
First and foremost, wind is an unlimited, free, renewable resource. Wind is a natural occurrence and harvesting the kinetic energy of wind doesn't affect currents or wind cycles in any way. Next, harvesting wind power is a clean, non-polluting way to generate electricity.
DISADVANTAGES
Firstly, constructing turbines and wind facilities is extremely expensive. The second disadvantage is technology immaturity. [1] High cost of energy can, in part, be addressed directly with technology innovations that increase reliability and energy output and lower system capital expenses.
Q11.Renewable energy sources are ones which don't run out - which can be renewed. We can keep using them and using them, and we'll never run out. Examples of renewable sources include wind, water power (hydroelectric), and solar power (light from the sun).
Non-renewable energy sources are ones which do run out. As we use them to generate energy, they get used up, and can't be used a second time. There are three main non-renewable energy sources, which are fast running out: coal, oil and natural gas.
Q12.Converting light energy to heat energy: Solar cookers concentrate sunlight onto a receiver such as a cooking pan. The interaction between the light energy and the receiver material converts light to heat and this is called conduction. This conversion is maximized by using materials that conduct and retain heat. Pots and pans used on solar cookers should be matte black in color to maximize the absorption.