The incorrect statement about the refractive index for a pair of media is:

$A$ light ray is incident on a transparent sphere of refractive index $\mu = \sqrt{2}$ at an angle of incidence $i = 45^{\circ}$. What is the total deviation of a ray that enters the sphere,undergoes two internal reflections,and then refracts out into the air (in $^{\circ}$)?

$A$ tank is filled with water to a height of $12.5 \;cm$. The apparent depth of a needle lying at the bottom of the tank is measured by a microscope to be $9.4 \;cm$. What is the refractive index of water?
If water is replaced by a liquid of refractive index $1.63$ up to the same height,by what distance would the microscope have to be moved to focus on the needle again?

The refractive index of water is $1.33$. The direction in which a man under water should look to see the setting sun is

Optical phenomena taking place for a mirror and a lens respectively are . . . . . . and . . . . . . .

In the figure shown here,the angle made by the light ray with the normal in the medium of refractive index $\sqrt{3}$ is.......$^o$