$A$ ray of light is incident at an angle of $9.3^{\circ}$ on one face of a small-angle prism with a refracting angle of $6^{\circ}$. If the ray of light emerges normally from the second face, the refractive index of the material of the prism is:

$A$ ray falls on a prism $ABC$ $(AB = BC)$ and travels as shown in the figure. The minimum refractive index of the prism material should be

$A$ 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:

Consider two equivalent,triangular hollow prisms $A$ and $B$ made of thin glass plates and arranged with negligible spacing as shown in the figure. $A$ beam of white light is incident on prism $A$ from the left. Given that the refractive index of water is inversely related to temperature,the beam to the right of prism $B$ would not appear white,if

The exit surface of a prism with refractive index $n$ is coated with a material having refractive index $\frac{n}{2}$. When this prism is set for minimum angle of deviation, it exactly meets the condition of the critical angle. The prism angle is . . . . . . (in $^{\circ}$)

For a symmetric (equilateral) prism,the prism formula can be written as