The average power output of a point source of an electromagnetic radiation is $1080 \,W$. The maximum value of the rms value of the electric field at a distance of $3 \,m$ from the source is (in $\,Vm^{-1}$)

In an electromagnetic wave,the amplitude of the electric field is $1 \ V/m$ and the frequency of the wave is $5 \times 10^{14} \ Hz$. The wave propagates in the positive $Z$-direction. The average energy density of the electric field in this wave is ........ $J \ m^{-3}$.

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

If the magnetic field in a plane electromagnetic wave is given by $\overrightarrow{B} = 3 \times 10^{-8} \sin (1.6 \times 10^{3} x + 48 \times 10^{10} t) \hat{j} \; T$,then what will be the expression for the electric field?

For the plane electromagnetic wave given by $E=E_0 \sin (\omega t-kx)$ and $B=B_0 \sin (\omega t-kx)$,the ratio of average electric energy density to average magnetic energy density is

The sun delivers $10^{3} \,W m^{-2}$ of electromagnetic flux on the Earth's surface. The total power that is incident on a roof of dimensions $6 \,m \times 30 \,m$ is . . . . . . .