The amplitude of the electric field in a parallel beam of plane electromagnetic waves of intensity $53.1 \ W \ m^{-2}$ is (Permittivity of free space $\epsilon_0 = 8.85 \times 10^{-12} \ C^2 \ N^{-1} \ m^{-2}$) (in $N \ C^{-1}$)

Electromagnetic waves travel in a medium which has relative permeability $1.3$ and relative permittivity $2.14$. Then the speed of the electromagnetic wave in the medium will be

In a plane electromagnetic wave,$U_E$ and $U_B$ are the average energy densities of the electric field and magnetic field,respectively. Then,which of the following is the correct option?

Pick out the statement which is not true.

How much time will it take for information to propagate over a distance of $30 \, km$ in space?

Statement-$I$ :- During propagation of electromagnetic wave,$\vec{E}$,$\vec{B}$ and direction of propagation are perpendicular to each other.
Statement-$II$ :- During propagation of electromagnetic wave,the energy density due to electric and magnetic fields are equal.