$A$ yellow light undergoes minimum deviation through a prism. If $i_1$ and $i_2$ are the angle of incidence and the angle of emergence respectively,then:

$A$ ray of light passes through an equilateral glass prism in such a manner that the angle of incidence is equal to the angle of emergence and each of these angles is equal to $\frac{3}{4}$ of the angle of the prism. The angle of deviation is (in $^{\circ}$)

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:

Which of the following diagrams correctly shows the dispersion of white light by a prism?

$A$ thin prism having refracting angle $10^{\circ}$ is made of glass of refractive index $1.42$. This prism is combined with another thin prism of glass of refractive index $1.7$. This combination produces dispersion without deviation. The refracting angle of the second prism should be....$^{\circ}$

$A$ prism $ABC$ of angle $30^\circ$ has its face $AC$ silvered. $A$ ray of light incident at an angle of $45^\circ$ at the face $AB$ retraces its path after refraction at face $AB$ and reflection at face $AC$. The refractive index of the material of the prism is