(a)[2]
Explain how the plates may function as a capacitor.
(b(i))[2]
Show that the average current $I$ in the ammeter is $I = CVf$.
(b(ii))[2]
For a potential difference $V$ of $180\,\text{V}$ and a switching frequency $f$ of $50\,\text{Hz}$, the average current $I$ in the ammeter is $2.5\,\mu\text{A}$. Calculate the capacitance, in pF, of the parallel plates.
(c)[2]
A second capacitor is added to the circuit in Fig. 6.2. The two capacitors are connected in parallel. State and explain the change, if any, in the average current in the ammeter.