In the diagram,a ray is passing through a broken prism. Find the angular deviation for the ray. (in $^{\circ}$)

$A$ prism $ABC$ of angle $30^\circ$ has its face $AC$ silvered. $A$ ray of light incident at an angle of $45^\circ$ at the face $AB$ retraces its path after refraction at face $AB$ and reflection at face $AC$. The refractive index of the material of the prism is

$A$ ray of light passes through an equilateral prism such that the angle of incidence is equal to the angle of emergence,and each of these angles is equal to $\left(\frac{3}{4}\right)^{th}$ of the angle of the prism. The angle of deviation is: (in $^{\circ}$)

$A$ prism has a refracting angle $A$. The second refracting surface of the prism is silvered. $A$ light ray falling on the first refracting surface with an angle of incidence $2A$ reaches the second surface and returns back along the same path due to reflection at the silvered surface. The refractive index of the material of the prism is:

In an equilateral prism,the ray undergoes minimum deviation when it is incident at an angle of $50^{\circ}$. The angle of minimum deviation is (in $^{\circ}$)

Angle of minimum deviation is equal to the half of the angle of prism in an equilateral prism. The refractive index of the prism is . . . . . . .