$A$ prism has a refracting angle $A$. The second refracting surface of the prism is silvered. $A$ light ray falling on the first refracting surface with an angle of incidence $2A$ reaches the second surface and returns back along the same path due to reflection at the silvered surface. The refractive index of the material of the prism is:

Angle of minimum deviation is equal to the half of the angle of prism in an equilateral prism. The refractive index of the prism is . . . . . . .

$A$ light ray enters through a right-angled prism at point $P$ with an angle of incidence of $30^{\circ}$ as shown in the figure. It travels through the prism parallel to its base $BC$ and emerges along the face $AC$. The refractive index of the prism 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:

$A$ ray of light is incident at an angle of incidence '$i$' on one surface of a prism of small angle '$A$' and emerges normally from the other surface. If the refractive index of the material of the prism is '$\mu$',then the angle of incidence is equal to

For the angle of minimum deviation of a prism to be equal to its refracting angle,the prism must be made of a material whose refractive index