Two polaroid sheets are placed one over the other with their axes inclined to each other at $30^{\circ}$. The ratio of the intensity of the unpolarised incident light and the polarised emergent light is

Two polaroids have their polarizing directions parallel so that the intensity of the transmitted light is maximum. The angle through which either polaroid must be turned so that the intensity of the transmitted light is dropped to one-half of the previous transmitted intensity is $.....^\circ$.

$n$ polarizing sheets are arranged such that each makes an angle $45^{\circ}$ with the preceding sheet. An unpolarized light of intensity $I$ is incident on this arrangement. The output intensity is found to be $\frac{I}{64}$. The value of $n$ will be:

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:

An unpolarised beam of light is incident on a group of three polarising sheets arranged such that the angle between the axes of any two adjacent sheets is $30^{\circ}$. The ratio of the intensities of polarised light emerging from the second and third sheets is

The angle between the polarizer and the analyzer is $45^o$. The percentage of polarized light passing through the analyzer is........$\%$