Q. Moment of inertia of a ring of mass $M$ and radius $R$ about an axis passing through the centre and perpendicular to the plane is $I$. What is the moment of inertia about its diameter
A) $I$
B) $\frac{I}{2}$
C) $\frac{I}{\sqrt{2}}$
D) $I + MR^{2}$
Explanation
(b) Moment of inertia of a ring of mass $M$ and radius $R$ about an axis passing through the centre and perpendicular to the plane
$I = MR^{2}$ …(i)
Moment of inertia of a ring about its diameter
$I_{diameter} = \frac{MR^{2}}{2} = \frac{I}{2}$ [Using (i)]
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.