A stationary horizontal disc is free to rotate about its axis. When a torque is applied on it, its kinetic energy as a function of $\theta ,$ where $\theta $ is the angle by which it has rotated, is given as $k\theta ^2.$ If its moment of inertia is $I$ then the angular acceleration of the disc is

  • [JEE MAIN 2019]
  • A

    $\frac {K}{I}\,\theta $

  • B

    $\frac {K}{2I}\,\theta $

  • C

    $\frac {K}{4I}\,\theta $

  • D

    $\frac {2K}{I}\,\theta $

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