A football of radius $R$ is kept on a hole of radius $r (r < R)$ made on a plank kept horizontally. One end of the plank is now lifted so that it gets tilted making an angle $\theta$ from the horizontal as shown in the figure below. The maximum value of $\theta$ so that the football does not start rolling down the plank satisfies (figure is schematic and not drawn to scale) -

223740-q

  • [IIT 2020]
  • A

    $\sin \theta=\frac{r}{R}$

  • B

    $\tan \theta=\frac{r}{R}$

  • C

    $\sin \theta=\frac{r}{2 R}$

  • D

    $\cos \theta=\frac{r}{2 R}$

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