$A$ thin prism of glass is placed in air and water successively. If $_a\mu _g = 3/2$ and $_a\mu _w = 4/3$,then the ratio of the deviation produced by the prism for a small angle of incidence when placed in air and water is

The angle of minimum deviation for a prism of refractive index $1.5$ is equal to the angle of the prism. The angle of the prism is . . . . . . . $(\sin 48^{\circ} 36^{\prime} = 0.75)$

$A$ light ray is incident on a prism of angle $A = 30^{\circ}$ at an angle of incidence of $60^{\circ}$. If the emergent ray makes an angle of $30^{\circ}$ with the incident ray,then find the refractive index of the prism $:-$

One face of a prism with a refracting angle of $30^{\circ}$ is coated with silver. $A$ ray incident on the other face at an angle of $45^{\circ}$ is refracted,reflected from the silver-coated face,and retraces its path. The refractive index of the prism is:

$A$ ray of light is incident at an angle of $9.3^{\circ}$ on one face of a small-angle prism with a refracting angle of $6^{\circ}$. If the ray of light emerges normally from the second face, the refractive index of the material of the prism is:

The diagram shows five isosceles right-angled prisms. $A$ light ray incident at $90^{\circ}$ at the first face emerges at the same angle with the normal from the last face. Which of the following relations will hold regarding the refractive indices?