Why two formulas for the electric field intensity and the magnetic induction created by a uniformly moving point charge?

摘要

A derivation of the electric field intensity and of the magnetic inductiongenerated by a uniformly moving point charge is presented. The derivation is inaccordance with the fact that the electric and magnetic fields of moving chargeare propagating from the charge with speed $c$ in empty space. The derivationis tailored for a special audience who knows the transformation of space, timeand fields and Coulomb's law in the rest frame of the point charge. It avoidsthe use of Maxwell's equations and the concept of retarded potential.