Question

A charged metallic ball is lowered into an insulated metal can.

The ball is made to touch bottom of the can. Then it is placed on the disc of electroscope shown below. Final

A. leaves of electroscope diverges
B. leaves of electroscope converges
C. leaves of electroscope remains unaffected
D. leaves of electroscope oscillates

Answer 1

Correct Answer - b
When charged metallic ball touches the bottom of can, all of its charge goes to the outer suface of the can. (Net charge on a conductor lies only on its surface).
When ball is withdrawn fron the can, it is uncharged. When ball is placed on the disc of electroscope .Final charge on the leaves is reduced so leaves electroscope converges.