A cord is wound round the circumference of wheel of radius $r$. The axis of the wheel is horizontal and the moment of inertia about it is $I. \,A$ weight $mg$ is attached to the cord at the end. The weight falls from rest. After falling through a distance $ 'h '$, the square of angular velocity of wheel will be ..... .

  • [JEE MAIN 2021]
  • A

    $\frac{2 mgh }{ I +2 mr ^{2}}$

  • B

    $\frac{2 mgh }{ I + mr ^{2}}$

  • C

    $2 gh$

  • D

    $\frac{2 gh }{ I + mr ^{2}}$

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  • [NEET 2018]

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  • [JEE MAIN 2022]