(a)[2]
State two uses of capacitors in electrical circuits, apart from smoothing direct current.
(b(i))[2]
In Fig. 7.1, the combined capacitance between terminals A and B is $4.0\,\mu\text{F}$. Two of the capacitors each have capacitance $C$, and each of the remaining capacitors has capacitance $3.0\,\mu\text{F}$. The potential difference (p.d.) across terminals A and B is $12\,\text{V}$. Determine the capacitance $C$.
(b(ii))[2]
Calculate the magnitude of the total positive charge transferred to the arrangement.
(b(iii)-1)[1]
Use your answer in (ii) to state the magnitude of the charge on one plate of a capacitor with capacitance $C$.
(b(iii)-2)[1]
Use your answer in (ii) to state the magnitude of the charge on one plate of a capacitor with capacitance $3.0\,\mu\text{F}$.