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A wheel is rotating freely at an angular...

A wheel is rotating freely at an angular speed of 800 rev/min on a shaft whose rotational inertia is negligible. A second wheel initially at rest with thrice the rotational inertia of the first is suddenly coupled to the same shaft. The fraction of original kinetic energy lost is

A

`2/3`

B

`1/3`

C

`1/4`

D

`1/2`

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The correct Answer is:
A
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