A simple pendulum oscillates slightly above a large horizontal metal plate. The bob is given a charge. The time period

Options

A. has no reffect, whatever be the nature of charge
B. always decreases, whatever be the nature of charge
C. always increases, whatever be the nature of charge
D. a increases or decreases depending upon the nature of charge.

Answer

B

Explanation

When any charge is given to the bob of the pendulum, it induces opposite charge on the metal plate, and hence a net force of attraction acts on the bob. Thus, the effective value of g increases.
So, From `T=2pisqrt((l)/(g_(off)))`, the value of T decreases.