Which of the following diagrams represents the variation of the electric field vector magnitude with time for a circularly polarized light?

Two polaroids are kept crossed to each other. Now one of them is rotated through an angle $45^{\circ}$. The percentage of incident light now transmitted through the system is ......$\%$

Longitudinal waves cannot

For light of intensity $I_0$,a polaroid is placed at an angle of $45^\circ$. What will be the intensity of the light passing through the polaroid after polarization?

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

Which of the following is a biaxial crystal?