NEET (UG) 2024 — Question 36

In a charging RC circuit, the conduction current $I$ flows in the wires. Between the capacitor plates, there is no conduction current, but the changing electric field produces a displacement current $I_d = \varepsilon_0 \frac{d\Phi_E}{dt}$. By the modified Ampere's law, the total current (conduction + displacement) is continuous. Applying Kirchhoff's current law at the capacitor plate, the displacement current must equal the conduction current in magnitude. The direction of the displacement current is the same as the direction of the conduction current because the electric field between the plates increases in the same direction as the current flows. Hence, the displacement current has magnitude $I$ and flows in the same direction as $I$.