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.