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 . . . . . . .

The refracting angle of a prism is $A,$ and the refractive index of the material of the prism is $\cot(A/2).$ The angle of minimum deviation is:

The exit surface of a prism with refractive index $n$ is coated with a material having refractive index $\frac{n}{2}$. When this prism is set for minimum angle of deviation,it exactly meets the condition of the critical angle. The prism angle is . . . . . . (in $^{\circ}$)

$A$ glass prism deviates the red and violet rays through $9^{\circ}$ and $11^{\circ}$ respectively. $A$ second prism of equal angle deviates them through $11^{\circ}$ and $13^{\circ}$ respectively. The ratio of dispersive power of the second prism to the first prism is

Monochromatic light passes through a prism. Compared to that in air, inside the prism the light's

For a thin symmetric prism made of glass (refractive index $1.5$),the ratio of the angle of incidence to the angle of minimum deviation is . . . . . . .