The angle of polarisation for a medium is $60^o$. What will be the critical angle for this medium?

$A$ parallel beam of monochromatic unpolarised light is incident on a transparent dielectric plate of refractive index $\mu = \sqrt{3}$. The reflected beam is completely polarised. Then the angle of incidence is....$^o$

$A$ camera equipped with a polariser is placed on a mountain to record only the reflected image of the sun from the surface of a sea,as shown in the figure. If the sun rises at $6.00 \, AM$ and sets at $6.00 \, PM$ during the summer,then at what time in the afternoon will the recorded image have the lowest intensity? Assume there are no clouds and the intensity of the sun at the sea surface is constant throughout the day. (Refractive index of water $= 1.33$)

The critical angle of a certain medium is $\sin^{-1}\left(\frac{3}{5}\right)$. The polarizing angle of the medium is

$A$ beam of light $AO$ is incident on a glass slab $(\mu = 1.54)$ in a direction as shown in the figure. The reflected ray $OB$ is passed through a Nicol prism. On viewing through the rotating Nicol prism,we find that $(\tan 57^{\circ} = 1.54)$.

$A$ 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 $\simeq \frac{4}{3}$)