$A$ spectrum is formed by a prism of dispersive power $\omega$. If the angle of deviation is $\delta$,then the angular dispersion is

The refractive index of a prism is $\sqrt{2}$ and the angle of the prism is $30^\circ$. One of the refracting surfaces of the prism is polished. $A$ monochromatic beam of light enters the prism and retraces its path. What is the angle of incidence at the first refracting surface of the prism in degrees (in $^\circ$)?

From the graph of angle of deviation $\delta$ versus angle of incidence $i$ for an equilateral prism, the refractive index of the material of the prism is:

For an isosceles prism of angle $A$ and refractive index $\mu$,it is found that the angle of minimum deviation $\delta_m=A$. Which of the following options is/are correct?
[$A$] At minimum deviation,the incident angle $i_1$ and the refracting angle $r_1$ at the first refracting surface are related by $r_1=\left(i_1 / 2\right)$.
[$B$] For this prism the refractive index $\mu$ and the angle of prism $A$ are related as $A=\frac{1}{2} \cos ^{-1}(\mu / 2)$.
[$C$] For this prism,the emergent ray at the second surface will be tangential to the surface when the angle of incidence at the first surface is $i_1=\sin ^{-1}\left[\sin A \sqrt{4 \cos ^2 \frac{A}{2}-1}-\cos A\right]$.
[$D$] For the angle of incidence $i_1=A$,the ray inside the prism is parallel to the base of the prism.

$A$ ray is incident at an angle of $53^{\circ}$ on a prism and emerges at an angle of $37^{\circ}$ as shown. If the angle of incidence is changed to $50^{\circ}$,which of the following is a possible value of the angle of emergence (in $^{\circ}$)?

$A$ ray of light suffers minimum deviation when incident on a prism having an angle of the prism equal to $60^{\circ}$. The refractive index of the prism material is $\sqrt{2}$. The angle of incidence (in degrees) is . . . . . . .