Conservation Laws, Electrodynamics, Poynting Vector, Poynting Theorem, Physics.
velocity v is given by Lorentz’s equation F = q (E + v × B). Thus, the work done while moving a distance dl, will be given by F.dl. Replacing dl with v dt, we can eliminate the second term since (v × B).v = 0. Further, for an infinitesimal volume dV, the charge q can be replaced in terms of the