Heat & Energy class 9

1.Why does the interior of a car become too hot when parked in the sun as compared to the temperature outside?

2.What is the reason of increase in carbon dioxide's share of the atmosphere?What is it's result?

3.Which gas is responsible for man-made climate change?

4.Is global warming a natural occurenocc?If not, who is responsible for it?

5.What is biogas?How is it obtained?State it's composition.

6.Is the electricity generated by a single windmill sufficient for commercial purpose?Explain.

7.State the principal advantages associated with solar cells.

8.Silicon used for making solar cells , is abundant in nature even then solar cells are costlier,why?

9.During heavy rains in a village, the rainwater carried excessive nitrogen compounds to a pind.How will it affect the growth of fish in the pond in the long run?

10. State ten percent law.

11.Why do water pipes burst during severe frost?

12.why are taps left dripping in sub-zero temperature during extremely cold season?

13.Why are soft drink bottles not filled completely?

14.why do fruits & vegetables get damaged during severe frost?

15.