Light waves can be polarized because

$A$ beam of natural light falls on a system of $5$ polaroids,which are arranged in succession such that the pass axis of each polaroid is turned through $60^{\circ}$ with respect to the preceding one. The fraction of the intensity of incident light that passes through the system is:

In an experiment,two polaroids are arranged such that the intensity of the polarised light emerged from the second polaroid is $37.5 \%$ of the intensity of the unpolarised light incident on the first polaroid. Then the angle between the axes of the two polaroids is (in $^{\circ}$)

Two polaroids $P_1$ and $P_2$ are placed with their axes perpendicular to each other. Unpolarised light of intensity $I_0$ is incident on $P_1$. $A$ third polaroid $P_3$ is kept in between $P_1$ and $P_2$ such that its axis makes an angle $45^{\circ}$ with that of $P_1$. The intensity of transmitted light through $P_2$ is

Unpolarized light of intensity $I$ passes through an ideal polarizer $A$. Another identical polarizer $B$ is placed behind $A$. The intensity of light beyond $B$ is found to be $\frac{I}{2}$. Now,another identical polarizer $C$ is placed between $A$ and $B$. The intensity beyond $B$ is now found to be $\frac{I}{8}$. The angle between polarizer $A$ and $C$ is: ......$^{\circ}$

$A$ beam of unpolarised light of intensity $I_0$ is passed through a polaroid $A$ and then through another polaroid $B$ which is oriented so that its principal plane makes an angle of $45^{\circ}$ relative to that of $A$. The intensity of the emergent light is