When a white light passes through a hollow prism,then

The angle of the prism is $30^o$. The rays incident at an angle of $60^o$ at one refracting face suffer a deviation of $30^o$. Then the angle of emergence is......$^o$

Three right-angled prisms of refractive indices $n_1$,$n_2$,and $n_3$ are fixed together using an optical glue as shown in the figure. If a ray passes through the prisms without suffering any deviation,then

$A$ graph is plotted between angle of deviation $(\delta)$ and angle of incidence $(i)$ for a prism. The nearly correct graph is

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:

The refracting angle of a prism is $A,$ and the refractive index of the material of the prism is $\cot(A/2).$ The angle of minimum deviation is: