A circular disc A and a ring B have same mass and same radius. If they are rotated with the same angular speed about their own axis, then

Options

A. A has less moment to inetia than B
B. A has less rotational kinetic energy than B
C. A and B have the same angular momentum
D. A has greater angular momentum than B

Answer

C

Explanation

Moment of inertia of disc
`I_("ring")=(MR^(2))/(2)`
Moment of inertia of ring `I_("ring")=MR^(2)`
Therefore, A has less moment of inertia than B because of which A has less rotational kinetic energy than B.