Question

Write the equation for the generalised 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

Generalised form of Ampere circuital law:

$\oint \underset{B}{\to }.\underset{dl}{\to }={\mu }_0(I_c+{\epsilon }_0\frac{d\varphi }{dt})$


It signifies that the source of magnetic field is not just due to the conduction electric current due to flow of charge but also due to the time rate of charge of electric field called displacement current.

During charging and discharging of a capacitor the electric field between the plates will change so there will be a change of electric flux between the platesdue to which there will be a displacement current.