If a polaroid is kept in the path of uniformly unpolarised light,the ratio of the intensity of the transmitted light to the intensity of the light when the polaroid was not kept in its path is:

$A$ beam of unpolarized light passes through a tourmaline crystal $A$ and then it passes through a second tourmaline crystal $B$ oriented so that its principal plane is parallel to that of $A$. The intensity of emergent light is $I_0$. Now $B$ is rotated by $45^{\circ}$ about the ray. The emergent light will have intensity $(\cos 45^{\circ} = \frac{1}{\sqrt{2}})$.

$A$ beam of natural light falls on a system of $6$ polaroids,which are arranged in succession such that each polaroid is turned through $30^\circ$ with respect to the preceding one. The percentage of incident intensity that passes through the system will be....$\%$

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 ................ $W/m^2$.

$A$ plane polarized light is incident on a polarizer with its pass axis making an angle $\theta$ with the $x-$axis,as shown in the figure. At four different values of $\theta$,namely $\theta = 8^o, 38^o, 188^o$ and $218^o$,the observed intensities are the same. What is the angle between the direction of polarization and the $x-$axis in degrees?

The transverse nature of light is shown by