Q. If the length of a pendulum is made 9 times and mass of the bob is made 4 times then the value of time period becomes
A) $3T$
B) $3/2T$
C) $4T$
D) $2T$
Explanation
(a) $T = 2\pi\sqrt{\frac{l}{g}} \Rightarrow T \propto \sqrt{l},$ hence if $l$ made 9 times $T$ becomes 3 times.
Also time period of simple pendulum does not depend on the mass of the bob
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.