TIME-DEPENDENT GENERALIZATIONS OF THE BIOT-SAVART AND COULOMB LAWS

Strictly, Coulomb's law and the Biot-Savart law determine the electric and magnetic fields for static sources only. Time-dependent generalizations of these two laws, introduced by Jefimenko, are used here to explore the applicability of Coulomb and Biot-Savart outside the static domain. The fact that Biot-Savart holds for some classes of time-dependent currents has led to much confusion in the literature, which this paper endeavors to dispel. To illustrate Jefimenko's equations, the standard Lienard-Wiechert fields of a point charge are derived.