A same torque is applied to a disc and a ring of equal mass and radii then (a) the ring will rotate with greater angular frequency. (b) both will rotate with same angular frequency. (c) the disc will rotate with greater angular frequency. (d) both will rotate with same angular velocity.

Answer: (c). Same mass and radius: Idisc = 1/2MR² < Iring = MR². Same torque: α = τ/I, so the disc has the larger angular acceleration. After the same time the disc spins faster. So the answer is (c): the disc rotates with greater angular frequency.

A same torque is applied to a disc and a ring of equal mass and radii… | MHT CET 2025 (26 Apr, Shift 2)

Q14MHT CET 2025 · 26 APR · SHIFT 2Easy

Rotational Kinematics & Dynamics

A same torque is applied to a disc and a ring of equal mass and radii then

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Answer: (c)

Same mass and radius: $I_{disc} = \frac{1}{2}MR^2 < I_{ring} = MR^2$ .
Same torque: $\alpha = \frac{\tau}{I}$ , so the disc has the larger angular acceleration.
After the same time the disc spins faster.
So the answer is (c): the disc rotates with greater angular frequency.

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