Question #98948

1 Answer
Sep 19, 2017

There is no general description of equation of energy of an EM wave.

However, in the wave picture of radiation, the Electric and magnetic fields can carry energy (equally distributed among both) and the corresponding energy density can be given as,

u=(ε0E22+B22μ0) where E and B are electric and magnetic field magnitudes.

Thus in a volume dτ, the corresponding electromagnetic energy is E=udτ

However, in the particle picture of radiation, it is considered to be a stream of fast moving particles called photons. In that case, the energy carried by each photon of frequency ν is,

E=hν where h is Planck's constant.