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 $^{\circ}$)

Unpolarised red light is incident on the surface of a lake at an incident angle $\theta_{R}$. An observer seeing the light reflected from the water surface through a polariser notices that on rotating the polariser,the intensity of light drops to zero at a certain orientation. The red light is replaced by unpolarised blue light. The observer sees the same effect with reflected blue light at an incident angle $\theta_{B}$. Then,

$A$ person lives in a high-rise building on the bank of a river $50\, m$ wide. Across the river is a well-lit tower of height $40\, m$. When the person,who is at a height of $10\, m$,looks through a polarizer at an appropriate angle at light of the tower reflecting from the river surface,he notes that the intensity of light coming from a distance $X$ from his building is the least,and this corresponds to the light coming from light bulbs at height $Y$ on the tower. The values of $X$ and $Y$ are respectively close to (refractive index of water $\simeq \frac{4}{3}$)

An unpolarized light beam travelling in air is incident on a medium of refractive index $1.73$ at Brewster's angle. Then

The polarising angle for a transparent medium is $\theta$ and $V$ is the speed of light in that medium. The relation between $\theta$ and $V$ is (where $c$ is the velocity of light in vacuum):

When a light ray is incident on the surface of a medium,the reflected ray is completely polarized. Then the angle between the reflected and refracted rays is (in $^{\circ}$)