Question

What is displacement current write its expression nd derive the expression?

Answer 1

Displacement current is defined as the current due to time varying electric field.
I'd(current)=d(phi)/dt

Answer 2

In electromagnetism, displacement current is a quantity appearing in Maxwell's equations that is defined in terms of the rate of change of electricdisplacement field. Displacement current has the units of electric current density, and it has an associatedmagnetic field just as actual currents do.