For cases where currents and electromagnetic fields vary slowly, the induced displacement current can be ignored (∂D/∂t = 0). This assumption, referred to as the quasistatic approximation, is widely used in modeling low-frequencies electromagnetics where the dimensions of the structure is small compared to the wavelength. With this approximation, rewrite
Maxwell’s equations (
Equation 2-1) in the following manner:
where Je is an externally generated current density and
v is the velocity of the conductor.