Why is the brilliance of a diamond observed?

$A$ fish is a little below the surface of a lake. If the critical angle is $49^\circ$,then the fish could see things above the water surface within an angular range of $\theta^\circ$ where

$A$ cut diamond sparkles because of its

The refractive index of glass is $\frac{3}{2}$ and that of water is $\frac{4}{3}$. The critical angle for a ray of light going from glass to water is

The figure shows a ray incident at an angle $i = \pi /3.$ If the plot drawn shows the variation of $|r - i|$ versus $\frac{\mu_1}{\mu_2} = k,$ ($r =$ angle of refraction) choose the < strong>wrong alternative.

$A$ ray of light incident parallel to the base $PQ$ of an isosceles right-angled triangular prism $PQR$ suffers two successive total internal reflections at the faces $PQ$ and $QR$ before emerging reversed in direction as shown below. If the refractive index of the material of the prism is $\mu$,then