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Standard XII

Physics

Moment of Inertia of a Disc

In which of t...

Question

In which of the following cases, the moment of inertia is greatest?
I. A thin circular ring of radius R and mass M rotating about its diameter.
II. A circular disc of radius R and mass M rotating about a direction perpendicular to disc at its centre.
III. A solid cylinder of radius R and mass M rotating about the axis of cylinder.

III

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Same in all the cases

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Solution

The correct option is C I
In case I, we have $I = M R^{2}$

In case II, we have $I = \frac{M R^{2}}{2}$

In case III, we have $I = \frac{M R^{2}}{2}$

Hence, we have maximum Moment of Inertia in case I.

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Similar questions

Q. Moment of Inertia

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I_{2} = M I

of circular disc about an axis perpendicular to the disc and passing through the centre.

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of solid cylinder about its axis.

I_{4} = M I

of solid sphere about its diameter.

Then :

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The correct option is C IIn case I, we have I=MR2In case II, we have I=MR22In case III, we have I=MR22Hence, we have maximum Moment of Inertia in case I.

The correct option is C I
In case I, we have $I = M R^{2}$

In case II, we have $I = \frac{M R^{2}}{2}$

In case III, we have $I = \frac{M R^{2}}{2}$

Hence, we have maximum Moment of Inertia in case I.