Q33. Which of the following cannot be charged easily by friction?
(a) A plastic scale
(b) A copper rod
(c) An inflated balloon
(d) A woollen cloth.
Q34. What damage is caused by lightning?
Q35. When a glass rod is rubbed with a piece of silk cloth the rod
(a) and the cloth both acquire positive charge.
(b) becomes positively charged while the cloth has a negative charge.
(c) and the cloth both acquire negative charge.
(d) becomes negatively charged while the cloth has a positive charge.
Q36. What will happen when the metal top of an electroscope is touched with a glass rod which has been rubbed with silk cloth? Give reason for your answer.
Q37. What happens when you touch the paper clip of a self-made Electroscope? Why does it happen? What is this process called?
Q38. How can we determine if an object is charged or not?
Q39. What is lightning conductor? How does it work?
How does a lightning conductor protect a tall building?
Q40. What are the various effects of an earthquake?
Q41. What will you do to protect yourself from lightning if you are in an open field?
Q42. Explain why a charged balloon is repelled by another charged balloon whereas an uncharged balloon is attracted by another charged balloon?