As shown in the figure,three identical polaroids $P_1$,$P_2$,and $P_3$ are placed one after another. The pass axis of $P_2$ and $P_3$ are inclined at angles of $60^{\circ}$ and $90^{\circ}$ with respect to the axis of $P_1$. The source $S$ has an intensity of $256 \text{ W/m}^2$. The intensity of light at point $O$ is $........... \text{ W/m}^2$.

The angle between the axes of a polariser and an analyser is $45^{\circ}$. If the intensity of the unpolarized light incident on the polariser is $I$,then the intensity of the light emerged from the analyser is

Choose the correct alternative regarding the polarisation of light.

Three linear polarisers are placed coaxially. The transmission axis of the first polariser is at $30^{\circ}$,the second one is at $60^{\circ}$,and the third at $90^{\circ}$ to the vertical,all in the clockwise sense. Each polariser additionally absorbs $10 \%$ of the light. If a vertically polarised beam of light of intensity $I=100 \, W/m^2$ is incident on this assembly of polarisers,then the final intensity of the transmitted light will be close to ................ $W/m^2$.

Light waves can be polarized if they are...

Unpolarised light from air is incident on the surface of a transparent medium of refractive index $1.414$ such that the reflected light is completely polarised. Match the angles given in List-$I$ with the corresponding values given in List-$II$.

$A$. Angle of reflection	$(i)$ $2 \sin^{-1} \left(\sqrt{\frac{2}{3}}\right)$
$B$. Angle of refraction	$(ii)$ $\sin^{-1} \left(\sqrt{\frac{2}{3}}\right) - \sin^{-1} \left(\frac{1}{\sqrt{3}}\right)$
$C$. Angle between incident and completely polarised light	$(iii)$ $\sin^{-1} \left(\frac{1}{\sqrt{3}}\right)$
$D$. Angle of deviation of the incident ray	$(iv)$ $\cos^{-1} \left(\frac{1}{\sqrt{3}}\right)$