The bob of a pendulum is positively charged.Another identical charge is placed at the point of suspension of the pendulum.The time period of pendulum

Options

A. T' gt T'
B. T' lt T'
C. T' = T'
D. Information not sufficient

Answer

C

Explanation

The point charge on a point of suspension always applies electric force along the string on the bob. Tension of the string gets affected but the restoring force for the pendulum which is just mg sin `theta` is not affected. Time period of the pendulum remains the same.