JEE Main 2023PhysicsRotational MotionEasyNumerical

JEE Main 2023Rotational Motion Question with Solution

JEE Main 2023 (06 Apr Shift 2)

Question

A ring and a solid sphere rotating about an axis passing through their centres have same radii of gyration. The axis of rotation is perpendicular to plane of ring. The ratio of radius of ring to that of sphere is 2x. The value of x is _____.

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Show full solutionCorrect answer: 5
Correct answer
5

Step-by-step explanation

The moment of inertia of the ring about an axis perpendicular to the plane of ring is Ir=mk2.

The moment of inertia of the sphere is 

Is=25mR2s

It is given that 

mk2=mR2r=25mRs2   ...(i)

From equation (i)

Rr=25Rs

From the question, it can be written that

RrRs=2x

RrRs=25x=5

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About this question

This is a previous-year question from JEE Main 2023, covering the Rotational Motion chapter of Physics. PrepSharp catalogues every PYQ from JEE Main with a verified answer key and step-by-step solution prepared by IIT alumni — so you can search by chapter, topic or year and revise efficiently.