The speed of electromagnetic waves in a medium is $1.5 \times 10^8 \ m/s$. If the relative permittivity of that medium is $2$,then its magnetic susceptibility is (speed of light in vacuum is $3 \times 10^8 \ m/s$).

Given below are two statements: one is labelled as Assertion $(A)$ and other is labelled as Reason $(R).$
Assertion $(A):$ Electromagnetic waves carry energy but not momentum.
Reason $(R):$ Mass of a photon is zero.
In the light of the above statements,choose the most appropriate answer from the options given below:

In the propagation of electromagnetic waves,the angle between the direction of propagation and the plane of polarisation is (in $^{\circ}$)

If the magnetic field of a light wave oscillates parallel to the $y-$ axis and is given by $B_y = B_m \sin(kz - \omega t)$,the direction of wave travel and the axis along which the electric vector oscillates are:

The magnetic field in a plane electromagnetic wave is given by, $B_{y} = 2 \times 10^{-7} \sin (\pi \times 10^{3} x + 3 \pi \times 10^{11} t) \; T$. Calculate the wavelength.

The pressure exerted by an electromagnetic wave of intensity $I \ (W/m^2)$ on a non-reflecting surface is [$c$ is the velocity of light].