Which property can be used to distinguish between light waves and sound waves?

Light passes successively through two polarimeter tubes,each of length $0.29 \ m$. The first tube contains a dextrorotatory solution of concentration $60 \ kg/m^3$ and specific rotation $0.01 \ rad \ m^2/kg$. The second tube contains a laevorotatory solution of concentration $30 \ kg/m^3$ and specific rotation $0.02 \ rad \ m^2/kg$. The net rotation produced is.......$^\circ$.

The wave property of electrons implies that they will show diffraction effects. Davisson and Germer demonstrated this by diffracting electrons from crystals. The law governing the diffraction from a crystal is obtained by requiring that electron waves reflected from the planes of atoms in a crystal interfere constructively. Which of the following phenomena establishes the transverse nature of light?

$A$ system of three polarizers $P_1, P_2, P_3$ is set up such that the pass axis of $P_3$ is crossed with respect to that of $P_1$. The pass axis of $P_2$ is inclined at $60^{\circ}$ to the pass axis of $P_3$. When a beam of unpolarized light of intensity $I_0$ is incident on $P_1$,the intensity of light transmitted by the three polarizers is $I$. The ratio $(I_0/I)$ equals (nearly)

$A$ 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 emergent light is:

The angle between the axes of a polariser and an analyser is $45^{\circ}$. If the intensity of the unpolarized light incident on the polariser is $I$,then the intensity of the light emerged from the analyser is