JEE Main202325 Jan 2023Morning ShiftPhysicsRotational MotionActual
I CM is moment of inertia of a circular disc about an axis (CM) passing through its center and perpendicular to the plane of disc. I AB is its moment of inertia about an axis AB perpendicular to plane and parallel to axis CM at a distance 2 3 R from center, where R is the radius of the disc. The ratio of I AB and I CM is x : 9 . The value of x is ______.
Correct answer
0
Step-by-step solution
We have, I CM = 1 2 M R 2   Since A B is parallel to diameter and at a distance of 2 3 R from it, using parallel axis theorem, I AB = m R 2 2 + m 2 R 3 2 = 17 18 m R 2 Thus, the ratio is ∴ I AB I CM = 17 18 M R 2 1 2 M R 2 = 17 9 Thus, x = 17