If the intensity of an electromagnetic wave is $0.02 \ W/m^2$ and its velocity in free space is $3 \times 10^8 \ m/s$,then the energy density of the radiation is ..... $J/m^3$.

$A$ plane electromagnetic wave has a frequency of $2.0 \times 10^{10} \ Hz$ and its energy density is $1.02 \times 10^{-8} \ J/m^3$ in vacuum. The amplitude of the magnetic field of the wave is close to $....nT$. (Given: $\frac{1}{4 \pi \varepsilon_0} = 9 \times 10^9 \ Nm^2/C^2$ and speed of light $c = 3 \times 10^8 \ m/s$)

Write the standard equation for a plane electromagnetic wave traveling in the $x$-direction.

$A$ plane electromagnetic wave of wavelength $\lambda$ has an intensity $I$. It is propagating along the positive $Y$-direction. The allowed expressions for the electric and magnetic fields are given by:

The speed of an electromagnetic wave in a vacuum depends upon the source of radiation.

The $rms$ value of the electric field of the light coming from the Sun is $720 \; N/C$. The average total energy density of the electromagnetic wave is