A table tennis ball which has been covered with a conducting... | Physics | SolveeIt | Solveeit

Today, August 18

Question

A table tennis ball which has been covered with a conducting paint is suspended by a silk thread so that it hangs between two metal plates. One plate is earthed. When the other plate is connected to a high voltage generator, the ball

A

is attracted to the high voltage plate and stays there

B

hangs with out moving

C

swings backward and forward hitting each plate in turn

D

is repelled to the earthed plate and stays there

Answer

swings backward and forward hitting each plate in turn

Explanation

Solution

When the other piate is connected to the high voltage generator, the negative charge induced on the ball cause attraction. When it strikes the $+ve$ plate charge distribution again takes piace. This causes repulsion. Hence, the ball swings backward and forward hitting each plate in tum.