Three identical polaroids $P_1, P_2$, and $P_3$ are placed one after another. The pass axes 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 has an intensity $I_0$. The intensity of light finally coming out is

$A$ polarizer and an analyzer are placed such that the intensity of the transmitted light is maximum. If the analyzer is rotated by $60^{\circ}$,find the intensity of the transmitted light.

Two linear polarisers are placed coaxially. The transmission axis of the first polariser is at $30^{\circ}$ from the vertical,while the second one is at $60^{\circ}$ from the vertical,both in the clockwise sense. If an unpolarised beam of light of intensity $I_{0}=20 \,W/m^{2}$ is incident on this pair of polarisers,then the intensities $I_{1}$ and $I_{2}$ transmitted by the first and second polarisers respectively,will be close to:

$A$ beam of plane polarized light falls normally on a polarizer of cross-sectional area $3 \times 10^{-4} \, m^2$. The flux of energy of the incident ray is $10^{-3} \, W$. The polarizer rotates with an angular frequency of $31.4 \, rad/s$. The energy of light passing through the polarizer per revolution is:

$A$ beam of light of intensity $I_0$ falls on a system of three polaroids which are arranged in succession such that the pass (transmission) axis is turned through $60^{\circ}$ with respect to the preceding one. The fraction of the incident light intensity that passes through the system is $\left(\cos 60^{\circ} = 1/2\right)$.

After passing through a polariser,a linearly polarised light of intensity $I$ is incident on an analyser making an angle of $30^{\circ}$ with that of the polariser. The intensity of light emitted from the analyser will be