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

$\sqrt{3}=\frac{\sin (60°)}{\sin r} \Rightarrow r=30°$

Since, ${\theta }_c={\sin }^{-1}\left(\frac{1}{\sqrt{3}}\right)=0.577$

At point Q, angle of incidence inside the prism is $i=45°$.

Since, $\sin i=\frac{1}{\sqrt{2}}$ is greater than $\sin {\theta }_c=\frac{1}{\sqrt{3}}$, ray gets totally internally reflected at face CD. Path of ray of light after point Q is shown in figure.

From the figure, we can see that angle between incident ray OP and emergent ray RS is $90°$.