MHT CET · Physics · Rotational Motion

A ring, a solid sphere and a disc have same mass and radius. Which of them have the largest moment of inertia?

A All have the same moment of inertia
B Solid sphere only
C Ring only
D Disc only

Verified Solution

Answer & Solution

Correct Answer

(C) Ring only

Step-by-step Solution

Detailed explanation

Formula for moment of inertia are listed below:
\(I_{\text {Ring }}=M R^2\)
\(I_{\text {Sphere }}=\frac{2}{5} M R^2\)
\(I_{\text {Disc }}=\frac{1}{2} M R^2\)
Ring has largest moment of inertia as the mass is distributed far away from the axis of rotation. Above formulas just confirm that.

Apply the relevant identity from the chapter and substitute the values established in the previous step, keeping the original constraint in view.

Use the simplified expression to isolate the unknown, then plug the result back into the question setup to confirm the working is internally consistent.

Cross-check against a boundary or limiting case. Both the dimensional balance and the qualitative behaviour at the extreme should agree with the candidate answer.

Combine the steps above to identify the correct option. The remaining choices each fail at least one of the consistency, dimensional, or boundary checks.

Same subject

Explore more questions on app

From MHT CET

Explore more questions on app