Q. The moment of inertia about an axis of a body which is rotating with angular velocity 1${\ rads}^{- 1}$ is numerically equal to
A) One-fourth of its rotational kinetic energy
B) Half of the rotational kinetic energy
C) Rotational kinetic energy
D) Twice the rotational kinetic energy
Explanation
(d) Rotational kinetic energy,
$KE = \frac{1}{2}I\omega^{2}$
Here, $\omega = 1\ rads^{- 1}$
$\therefore$ $KE = \frac{1}{2}I \times I$
or $I = 2\ KE$
$ie$, moment of inertia about an axis of a body is twice the rotational kinetic energy.
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.