$A$ prism of angle $10^o$ and refractive index $n=1.602$ is combined with another prism of refractive index $n=1.500$ such that the net deviation produced is zero. What is the angle of the second prism?

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 $^{\circ}$)

$A$ ray falls on a prism $ABC$ $(AB = BC)$ and travels as shown in the figure. The minimum refractive index of the prism material should be

$A$ ray of light is incident normally on one face of a $30^{\circ}-60^{\circ}-90^{\circ}$ prism of refractive index $5/3$ immersed in water of refractive index $4/3$ as shown in the figure.

$A$ deviation of $2^{\circ}$ is produced in the yellow ray when prisms of crown and flint glass are achromatically combined. Taking dispersive powers of crown and flint glass as $0.02$ and $0.03$ respectively and refractive indices for yellow light for these glasses as $1.5$ and $1.6$ respectively,the refracting angle for the crown glass prism will be $........\,^{\circ}$ (in degrees) (Round off to the nearest integer).

Define the angle of minimum deviation.