Practice question
Question
What is the effect of doubling the radius of a rotating disk on its moment of inertia, assuming mass remains constant?
Explanation
For a disk, I = 12MR2. Doubling R increases R2 by a factor of 4, so I increases by a factor of 4 if M is constant. As per NCERT, applying relevant law/formula with correct units and sign convention leads to It quadruples. This satisfies dimensional consistency and physical conditions given, so option B is scientifically correct.