In the given figure,at the water-air interface,a light ray is incident at the critical angle. Find the value of $\mu_g$.

Three transparent media of refractive indices $\mu_1, \mu_2, \mu_3$,respectively,are stacked as shown below. $A$ ray of light follows the path shown. No light enters the third medium. Then,

For a given pair of transparent media,the critical angle is maximum for which colour?

White light is incident on the interface of glass and air as shown in the figure. If green light is just totally internally reflected,then the reflected rays inside the glass contain:

$A$ ray of light is incident at an angle $i$ from a denser to a rarer medium. The reflected and the refracted rays are mutually perpendicular. The angle of reflection is $r$ and the angle of refraction is $r'$. Then the critical angle $C$ will be:

$A$ jar of height $h$ is filled with a transparent liquid of refractive index $\mu$. At the centre of the jar on the bottom surface is a dot. Find the minimum diameter of a disc,such that when placed on the top surface symmetrically about the centre,the dot is invisible.