Which of the following statements indicates that light waves are transverse?

Three polaroid sheets are kept parallel to each other such that the first and the last are crossed. Unpolarised light of intensity $32 \ W m^{-2}$ falls normally on the first sheet and passes through all the polaroid sheets. If the intensity of the emerging light from the third sheet is $3 \ W m^{-2}$,then the angle between the axes of the first two polaroid sheets is: (in $^{\circ}$)

$A$ plane polarized light is incident normally on a tourmaline plate. Its $\vec{E}$ vectors make an angle of $60^{\circ}$ with the optic axis of the plate. Find the percentage difference between initial and final intensities. (in $\%$)

$A$ polaroid is placed at $45^o$ to an incoming light of intensity $I_0$. Now the intensity of light passing through the polaroid after polarisation would be

The specific rotation of a sugar solution is $0.01 \ SI$ units. $A$ $200 \ kg/m^3$ solution of impure sugar is taken in a polarimeter tube of length $0.25 \ m$,and an optical rotation of $0.4 \ rad$ is observed. The percentage of purity of sugar in the sample is.....$\%$

Two polaroids are oriented with their planes perpendicular to incident light and their transmission axes making an angle of $30^{\circ}$ with each other. What fraction of the incident unpolarised light is transmitted? (Express as a percentage)