Solution: A current flowing in the circuit can be physically measured using an AC amperemeter. The current may be
calculated using circuit concepts, and since current in a closed circuit is the same everywhere in the circuit, this must also
be equal to the displacement current in the capacitor. A second method is to calculate the electric flux density D in the
capacitor and then calculate ∂D/∂t in the capacitor to obtain the displacement current density.
Method (1) The current in the circuit in Figure 11.1a is