The polarising angle of a transparent medium is $\theta$. Let the speed of light in the medium be $v$. Then the relation between $\theta$ and $v$ is [where $c$ is the velocity of light in air].

The angle of incidence of light falling on a material is $60^{\circ}$,and the reflected light is completely polarized. The speed of the refracted ray inside the material (in $m/s$) is:

The polarising angle for water is $53^\circ 4'$. If light is incident at this angle on the surface of water and reflected, the angle of refraction is:

$A$ ray of light is incident on the surface of a glass plate at Brewster's angle $\phi$. If $\mu$ is the refractive index of glass with respect to air,then the angle between the reflected and the refracted ray is:

The polarizing angle of glass is $57^{\circ}$. $A$ ray of light which is incident at this angle will have an angle of refraction as (in $^{\circ}$)

$A$ person lives in a high-rise building at a height of $30 \ m$ on the bank of a river. Across the river is a well-lit tower of height $60 \ m$. When the person looks through a polarizer at an appropriate angle at light from the top of the tower reflecting from the river surface,he finds the intensity of light is least. If the refractive index of water is $\frac{4}{3}$,the width of the river is ...... $m$.