The refractive index of material of prism shown in figure is

Light is incident normally on the short face of a $30°-60°-90°$prism. A liquid is poured on the hypotenuse of the prism. If the refractive index of the prism is $\sqrt{3}$ , find the maximum refractive index of the liquid so that light is totally reflected

In the figure $ABC$ is the cross-section of a right angled prism and $BCDE$ is the cross-section of a glass slab. The value of $\theta$. So that light incident normally on the face $AB$ does not cross the face $BC$ is (given ${\sin }^{-1}\left(\frac{3}{5}\right)=37°$ )

Where, $\angle BAC=\theta$.

$n$ number of identical equilateral prisms are kept in contact as shown in figure. If deviation through a single prism is $\delta$. Then ( $n, m$ are integers)

A plane mirror is placed horizontally inside water $\left(\mu =\frac{4}{3}\right).$ A ray falls normally on it. The mirror is rotated by angle $\theta$ such that after reflection, the ray does not come out of water. The minimum value of $\theta$ is

Figure shows a torch sending a parallel beam of light fixed on a wall and a plane mirror which forms a spot on the wall. As the mirror moves towards the wall, the spot on the wall moves