Which of the following is a dichroic crystal?

Indicate the signals used for unpolarised,polarised,and partially polarised light.

Two polaroids are placed in the path of an unpolarised beam of intensity $I_0$ such that no light is emitted from the second polaroid. If a third polaroid,whose polarisation axis makes an angle $\theta$ with the polarisation axis of the first polaroid,is placed between these polaroids,then the intensity of light emerging from the last polaroid will be:

Two polaroids $A$ and $B$ are placed in such a way that the pass-axis of polaroids are perpendicular to each other. Now,another polaroid $C$ is placed between $A$ and $B$ bisecting the angle between them. If the intensity of unpolarised light is $I_0$,then the intensity of transmitted light after passing through polaroid $B$ will be:

$A$ $300 \, mm$ long tube contains $60 \, cm^3$ of a concentrated sugar solution. When placed in a polarimeter,it produces an optical rotation of $10^\circ$. If the specific rotation of sugar is $60^\circ$,calculate the amount of sugar in grams present in the tube.

An optically active compound: