The graph showing the dependence of intensity of transmitted light on the angle between polariser and analyser is ($I_0$ is intensity of plane polarised light)

$A$ beam of light $AO$ is incident on a glass slab $(\mu = 1.54)$ in a direction as shown in the diagram. The reflected ray $OB$ is passed through a polaroid. On viewing through the polaroid,we find that on rotating the polaroid: (Given $\tan 57^{\circ} = 1.54$)

What is partially polarised light?

Unpolarized light of intensity $I$ is incident on a system of two polarizers,$A$ followed by $B$. The intensity of emergent light is $I/2$. If a third polarizer $C$ is placed between $A$ and $B$,the intensity of emergent light is reduced to $I/3$. The angle between the polarizers $A$ and $C$ is $\theta$. Then:

Light waves can be polarized because

Which of the following phenomena can be demonstrated by light,but not with sound waves in an air column?