Polarised glass is used in sunglasses because

$A$ light beam has an amplitude $A$,and the angle between the analyser and the polariser is $60^o$. What is the amplitude of the light reflected by the analyser?

Unpolarised light of intensity $I_0$ is incident on a polarizer. What is the percentage of the intensity of light that gets transmitted from the polarizer (in $\%$)?

Explain the polarization of light by a thin plastic-like sheet.

$V_o$ and $V_E$ represent the velocities,$\mu_o$ and $\mu_E$ represent the refractive indices of ordinary and extraordinary rays for a doubly refracting crystal. Then:

$A$ mixture of plane polarised and unpolarised light falls normally on a polarizing sheet. On rotating the polarizing sheet about the direction of the incident beam,the transmitted intensity varies by a factor of $4$. Find the ratio of the intensities $I_P$ and $I_0$,respectively of the polarized and unpolarized components in the incident beam.