Q. A simple pendulum of period $T$ has a metal bob which is negatively charged. If it is allowed to oscillate above a positively charged metal plate, its period will
A) Remains equal to $T$
B) Less than $T$
C) Greater than $T$
D) Infinite
Explanation
(b) When a negatively charged pendulum oscillates over a positively charged plate then effective value of $g$ increases so according to $T = 2\pi\sqrt{\frac{1}{g}},T$ decreases
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.