$A$ plane electromagnetic wave is given by $E_z = 100 \cos(6 \times 10^8 t + 4x) \text{ V/m}$. The refractive index of the medium in which the wave is traveling is:

In an electromagnetic wave,the amplitude of the electric field is $1 \ V/m$. The frequency of the wave is $5 \times 10^{14} \ Hz$. The wave is propagating along the $z$-axis. The average energy density of the electric field,in $J/m^3$,will be:

If $\vec{E}$ and $\vec{B}$ are the electric field and magnetic field vectors of an electromagnetic wave respectively,then what is the direction of propagation of the electromagnetic wave?

The $rms$ value of the electric field of the light coming from the sun is $720 \ N \ C^{-1}$. The average energy density of the electromagnetic wave is $...... \ J \ m^{-3}$.

Suppose that the intensity of a laser is $\left(\frac{315}{\pi}\right) \ W/m^2$. The $rms$ electric field,in units of $V/m$,associated with this source is close to the nearest integer. Given: $\epsilon_0 = 8.86 \times 10^{-12} \ C^2 N^{-1} m^{-2}$ and $c = 3 \times 10^8 \ m/s$.

The oscillating electric and magnetic vectors of an electromagnetic wave are oriented along