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

Light rays from a source are incident on a glass prism of refractive index $\mu$ and prism angle $\alpha$. At near-normal incidence,the angle of deviation of the emerging rays is:

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

The refractive index of the material of a small-angled prism is $1.6$. If the angle of minimum deviation is $4.2^{\circ}$, the angle of the prism is: (in $^{\circ}$)

$A$ thin glass prism of angle $9^{\circ}$ with refractive index $1.4$ is combined with another glass prism of refractive index $1.6$ as shown in the figure. The combination of the prisms provides dispersion without deviation. Determine the angle $(A)$ of the second prism. (in $^{\circ}$)

When a ray of light is incident normally on one refracting surface of an equilateral prism (Refractive index of the material of the prism $= 1.5$),what happens to the ray at the second refracting surface?