A simple pendulum has time period `T` The bob is given negative charge and surface below it is given positive change new time period will be

Options

A. less than T
B. greater than T
C. equal to T
D. infinite

Answer

A

Explanation

The electric force on bob will act downwards along with the gravity and this increases effective gravitational acceleration for the pendulum. We know that time period of simple pendulum is given by `T=2pisqrt(l/g_"eff")`
Therefore, the time period will decrease.