If the refractive angles of two prisms made of crown glass are $10^o$ and $20^o$ respectively,then the ratio of their angular dispersions will be

When a glass prism of refracting angle $60^{\circ}$ is immersed in a liquid, its angle of minimum deviation is $30^{\circ}$. The critical angle of glass with respect to the liquid medium is (in $^{\circ}$)

$A$ small-angled prism is made of a material of refractive index $\frac{3}{2}$. The ratio of the angles of minimum deviation when the prism is placed in air and in water of refractive index $\frac{4}{3}$ is:

$A$ monochromatic ray of light is incident normally on a thin prism of refracting angle $A$. The ray is deviated through an angle $(1.15)^{\circ}$ in passing through the prism. The ray reflected internally from the second face emerges from the first face making an angle of $(6.3)^{\circ}$ with the incident ray. 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 of the prism is

An equilateral prism $P$ produces a minimum deviation for a given light ray. Additional prisms $Q$ and $R$ of the same shape and material are placed as shown in the figure. The ray will experience: