Q. A simple pendulum is made of a body which is a hollow sphere containing mercury suspended by means of a wire. If a little mercury is drained off, the period of pendulum will
A) Remains unchanged
B) Increase
C) Decrease
D) Become erratic
Explanation
(b) When a little mercury is drained off, the position of $c.g.$ of ball falls ($w.r.t.$ fixed end) so that effective length of pendulum increases hence $T$ increases
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.