A ray $OP$ of monochromatic light is incident on the face $AB$ of prism $ABCD$ near vertex $B$ at an incident angle of $60^{\circ }$ (see figure). If the refractive index of the material of the prism is $\sqrt{3}$, which of the following is (are) correct?

Ray OP goes parallel to the side BC. Hence the angle of incidence of this ray on the side CD becomes $45^{\circ }$.

Applying Snell's Law at the point Q,

$\sqrt{3}\sin 45^{\circ }=\sin r>1$

Hence, this is a case of total internal reflection.

Thus the angle of incidence on Q is equal to the angle of reflection.

This forms $30^{\circ }$ as angle of incidence on side AD.

By Snell's Law,

$\sqrt{3}\sin 30^{\circ }=\sin r=\frac{\sqrt{3}}{2}$

$⟹r=60^{\circ }$

Thus the angle between rays OP and RS is $90^{\circ }$.