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

The refractive index of a prism with apex angle $A$ is $\cot(A/2)$. The angle of minimum deviation is:

$A$ ray of monochromatic light is passing through an equilateral prism $(ABC)$ as shown in the figure. The refracted ray $(QR)$ is parallel to its base $(BC)$ and the angle of incidence $(i)$ is $50^\circ$. Then the angle of deviation $(\delta)$ is: (in $^\circ$)

$A$ prism of refractive index $\sqrt{2}$ has a refracting angle of $60^{\circ}$. At what angle must a ray be incident on it so that it suffers minimum deviation (in $^{\circ}$)?

Three thin prisms are combined as shown in the figure. The refractive indices of the crown glass for red,yellow,and violet rays are ${\mu _r}, {\mu _y}$ and ${\mu _v}$ respectively,and those for the flint glass are ${\mu _r}', {\mu _y}'$ and ${\mu _v}'$ respectively. If there is no net deviation in the yellow ray,then the ratio $A'/A$ will be:

$A$ parallel beam of light is incident on a thin prism with a prism angle of $\frac{4}{\pi}$ degrees. The refractive index of the prism is $1.5$. The focal length of the lens is $60 \ cm$. The coordinates of the converging point of the beam are: