$A$ light ray is incident by grazing one of the faces of a prism. After refraction,the ray does not emerge out from the other face. What should be the angle of the prism if the critical angle is $C$?

The angle of deviation through a prism is minimum when
$(A)$ Incident ray and emergent ray are symmetric to the prism
$(B)$ The refracted ray inside the prism becomes parallel to its base
$(C)$ Angle of incidence is equal to that of the angle of emergence
$(D)$ When angle of emergence is double the angle of incidence
Choose the correct answer from the options given below

Three prisms $1, 2$ and $3$ have the prism angle $A = 60^o$,but their refractive indices are respectively $1.4, 1.5$ and $1.6$. If $\delta_1, \delta_2, \delta_3$ be their respective angles of deviation,then:

One face of the glass prism is silver polished. $A$ light ray falls at an angle of $45^{\circ}$ on the other face. After refraction,it is subsequently reflected from the silvered face and then retraces its path. The refracting angle of the prism is $30^{\circ}$. The refractive index of the prism is

One of the refractive surfaces of a prism of angle $30^{\circ}$ is silvered. $A$ ray of light incident at an angle of $60^{\circ}$ retraces its path. The refractive index of the material of the prism is:

$A$ light ray is incident on a prism at an angle of $60^{\circ}$ and the refracting angle of the prism is $30^{\circ}$. The emergent ray makes an angle of $30^{\circ}$ with the incident ray. The refractive index of the prism is ...