Question

A hollow sphere partly filled with water has moment of inertia $I$ when it is rotating about its own axis at an angular velocity $\omega$. If its angular velocity is doubled then its moment of inertia becomes:

• A. Less than $I$
• B. More than $I$
• C. $I$
• D. zero

Answer 1

The correct option is B More than $I$

Hollow sphere is partially filled with water and rotating with $\omega$.
When $\omega$ increases the water concentrates on the surface of the sphere, thus the mass moves away from the axis of rotation, due which the moment of inertia of the system will increase.