CBSE Class 12 · 2011 · All India · EM WavesShort Answer

While the capacitor charges, a conduction current $i_c$ flows in the wires but no charge crosses the gap between the plates.
Applying Ampere's law $\oint \vec{B}\cdot d\vec{l}={\mu }_0{i}_c$ to two surfaces bounded by the same loop --- one cut by the wire, one passing between the plates --- gives different answers, which is inconsistent.
Maxwell removed the inconsistency by adding the displacement current $i_d={\epsilon }_{0}d{\Phi }_E/dt$, arising from the changing electric flux between the plates, so the generalized law is

Between the plates $i_c=0$ but $i_d\ne 0$, and the two surfaces now give the same $\vec{B}$.