Question

What is displacement current?

Hint:

Displacement current arises due to a changing electric field in a capacitor and contributes to the total current in the circuit.

Answer 1

Step 1: Definition of displacement current.
Displacement current is a term introduced by Maxwell to account for the changing electric field in a capacitor when the charge on the capacitor plates changes. It is given by: \[ I_d = \epsilon_0 \frac{d\Phi_E}{dt} \] where \( I_d \) is the displacement current, \( \epsilon_0 \) is the permittivity of free space, and \( \frac{d\Phi_E}{dt} \) is the rate of change of the electric flux \( \Phi_E \) through the capacitor.
Step 2: Explanation.
The displacement current is not an actual current in the traditional sense, as it does not involve the flow of charge. However, it acts like a current in that it produces a magnetic field similar to a real current. The concept of displacement current was essential for Maxwell to unify the equations of electricity and magnetism.
Step 3: Conclusion.
Displacement current is defined as the rate of change of electric flux in a capacitor, and it plays a key role in the consistency of Maxwell's equations.