Question

Write the expression for the generalized form of Ampere's circuital law. Discuss its significance and describe briefly how the concept of displacement current is explained through charging/discharging of a capacitor in an electric circuit

Answer 1

Ampere's Circuital Law states that the line integral of magnetic field induction equals the current enclosed times the permeability.

$\oint \overrightarrow{B}.\overrightarrow{dl}={\mu }_o{I}_{enclosed}$

A capacitor is separated by a region of insulator. During charging/discharging of capacitor, electric current flows in the circuit. However, no actual charge flows in the insulator region of the capacitor. This demands the needs to incorporate a new fictitious displacement current $I_D$ in the region which gives rise to a magnetic field in the region.