Q. Two rotating bodies A and B of masses m and 2m with moments of inertia $I_A$ and $I_B$ ($I_B > I_A$) have equal kinetic energy of rotation. If $L_A$ and $L_B$ be their angular momenta respectively, then
A) $L_A = \frac{L_B}{2}$
B) $L_A = 2L_B$
C) $L_B > L_A$
D) $L_A > L_B$
Explanation
[Solution] $L = \sqrt{2IK}$; with equal K, larger I gives larger L, so $L_B > L_A$. Answer (3).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.