May/June 2026 Paper 43

Define the capacitance of a parallel plate capacitor.

Two capacitors X and Y have capacitances $C_X$ and $C_Y$ respectively. The capacitors are connected in parallel to a supply that has electromotive force (e.m.f.) $E$, as shown in Figure 5.1.

Derive the expression for the relationship between $C_X$, $C_Y$ and the combined capacitance $C_T$ of the circuit.

Two capacitors are connected in series to a supply that has e.m.f. $6.00\text{ V}$. One of the capacitors has capacitance $C$ and the other has capacitance $2C$. The total energy stored by the two capacitors is $1.30\text{ mJ}$. Calculate $C$ in $\mu \text{F}$.