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

$A$ prism has a refracting angle of $30^\circ$ and a refractive index of $\mu = \sqrt{2}$. One of its faces is silvered. $A$ ray of light incident on the other face retraces its path. What is the angle of incidence in degrees?

White light is passed through a prism whose angle is $5^o$. If the refractive indices for rays of red and blue colour are respectively $1.64$ and $1.66$,the angle of deviation between the two colours will be.....$^o$.

For a prism of angle $\pi/3$,the angle of minimum deviation is $\pi/6$. If the velocity of light in vacuum is $3 \times 10^{8} \text{ m/s}$,then the velocity of light in the material of the prism is:

$A$ prism has a refracting angle '$A$'. The second refracting surface of the prism is silvered. $A$ light ray falling on the first refracting surface with an angle of incidence '$2A$' reaches the second surface and returns back through the same path due to reflection at the silvered surface. The refractive index of the material of the prism is:

The graph between angle of deviation $(\delta)$ and angle of incidence $(i)$ for a triangular prism is represented by :-