$A$ light ray is incident on a prism of angle $A = 30^{\circ}$ at an angle of incidence of $60^{\circ}$. If the emergent ray makes an angle of $30^{\circ}$ with the incident ray,then find the refractive index of the prism $:-$

$A$ light ray is incident normally on one surface of an equilateral prism. The angle of deviation of the light ray is (refractive index of the material of the prism $=\sqrt{2}$) (in $^{\circ}$)

$A$ light ray is incident on an equilateral glass prism placed on a horizontal table. Which of the following is true for the condition of minimum deviation?

$A$ prism of refracting angle $60^\circ$ is made with a material of refractive index $\mu$. For a certain wavelength of light,the angle of minimum deviation is $30^\circ$. For this wavelength,the value of the refractive index of the material is:

$A$ monochromatic light is incident from air on a refracting surface of a prism of angle $A = 75^{\circ}$ and refractive index $n_0 = \sqrt{3}$. The other refracting surface of the prism is coated by a thin film of material of refractive index $n$ as shown in the figure. The light suffers total internal reflection at the coated prism surface for an incidence angle of $\theta \leq 60^{\circ}$. The value of $n^2$ is:

$A$ prism of crown glass with a prism angle of $9^{\circ}$ and a prism of flint glass are used to make a direct vision spectroscope. If the refractive indices of crown and flint glass are $1.40$ and $1.60$ respectively,then the refracting angle of the flint glass prism will be.....$^{\circ}$