CBSE Important Questions

Q. 1. Name the following:

1. Two renewable sources of energy (non - conventional) 2
2. Two non-renewable or conventional sources of energy
3. Two forms of energy usually used at homes
4. ) The radiation emitted from a hot source
5. The component of sunlight that is absorbed by the ozone layer of the atmosphere.
6. Two activities in our daily life in which solar energy is used [Born on January 17, 1706]
7. The kind of surface that absorbs maximum heat
8. The device that directly converts solar energy into electrical energy
9. The range of temperature attained inside a box-type solar cooker placed in the sun for 2-3 hours
10. The two elements which are used to fabricate solar cells

Q. 2. State an important characteristic of a source of energy.

Q. 3. Which component of sun's energy is responsible for drying clothes?

Q. 4. What type of energy is possessed by wind?

Q. 5. Though a hot iron emits radiations, it is not visible to us. Why?

Q. 6. What type of radiations is emitted by a 100 W electric bulb?

Q. 7. How is the conductivity of a semi-conductor affected when light falls on it?

Q. 8. What is the main cause for winds to blow?

Q. 9. What is the minimum wind speed required for generating electricity in a wind mill?

Q. 10. What is a wind farm?

Q. 11. What is the principle involved in the working of the thermal power plant?

Q. 12. What is the energy conversion involved in a thermal power plant?

Q. 13. What is Biomass?

Q. 14. What is biogas?

Q. 15. Write the principle of the windmill?

Q. 16. What are hot spots?

Q. 17. What is nuclear fission reaction?

Q. 18. A sheet of glass is used in solar heating devices. Why?

Q. 19. Explain the construction and working of a hydro-electric power plant with a neat schematic diagram.

Q. 20. Give two main differences between renewable and non-renewable sources of energy.