For a thin prism,if the angle of prism is $4^{\circ}$ and the refractive index is $1.6$,then the angle of minimum deviation will be . . . . . . . (in $^{\circ}$)

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

In the position of minimum deviation when a ray of yellow light passes through a prism,its angle of incidence is

$A$ 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 critical angle between an equilateral prism and air is $45^o$. If the incident ray is perpendicular to the refracting surface,then

$A$ light ray is incident on a prism at an angle of $45^o$ and produces minimum deviation. If the refractive index of the prism is $\sqrt{2}$,then the prism angle is .......... $^o$.