Question

What is displacement current in electromagnetic field?

Answer 1

Definition of displacement current:

The current which is produced in a region due to varying electric flux or electric field is called displacement current. Generally denoted by Id (suffix).

Equation for displacement current:

Let at any instant, q be the charge on each plate on a parallel plate capacitor, during the process of charging.

Electric field at any point between the two plates:

E = q/ε₀A, where A = common area of two plates.

Thus, Electric flux, Φ = EAcosθ = EA [Since θ = 0]

Or Φ = (q/ε₀A)/A

Or Φ = q/ε₀

Or q = ε₀ Φ

Or dq/dt = ε₀ dΦ/dt

Or Id = ε₀A dE/dt [Since Φ = EA]

which is equation for displacement current.

Answer 2

an electromagnetic field is a classical field produced by moving electric charges. It is the field

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described by classical electrodynamics and is the classical counterpart to the quantized electromagnetic field tensor in quantum electrodynamics .