For a plane electromagnetic wave,which of the following quantities has an average value of zero?

The energy density associated with the electric field $\overrightarrow{E}$ and magnetic field $\overrightarrow{B}$ of an electromagnetic wave in free space is given by ($\epsilon_0$ - permittivity of free space,$\mu_0$ - permeability of free space):

If ${\varepsilon _0}$ and ${\mu _0}$ are respectively the electric permittivity and the magnetic permeability of free space,and ${\varepsilon}$ and ${\mu}$ are the corresponding quantities in a medium,the refractive index of the medium is:

Energy stored in electromagnetic oscillations is in the form of

Which one of the following is the property of a monochromatic,plane electromagnetic wave in free space?

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 $...... \ J \ m^{-3}$.