The relation between the critical angles of water and glass is:

$A$ point source of light is placed at a distance $h$ below the surface of a large deep lake. What is the percentage of light energy that escapes directly from the water surface if the refractive index $\mu$ of the water is $4/3$ (in $\%$)? (Neglect partial reflection)

The critical angle for diamond with respect to air is nearly (in $^{\circ}$)

$A$ beam of light is incident from air on the surface of a liquid. The angle of incidence is $\theta$ and the angle of refraction is $\alpha$. If the critical angle for the liquid when surrounded by air is $\theta_c$,then $\sin \theta_c$ is:

$A$ ray of light is incident normally on one face of a right-angled isosceles prism. It then grazes the hypotenuse. The refractive index of the material of the prism is

$A$ cut diamond sparkles because of its