Physics 9702 · AS & A Level

Energy stored in a capacitor

9 practice questions on Energy stored in a capacitor, with worked solutions and instant marking.

A capacitor is made of two metal plates with an insulator between them, as illustrated in Fig. 3.1. The potential difference across the plates is $V$. Fig. 3.2 shows how the magnitude of the charge $Q$ on one plate varies with $V$.

May/June 2011

A capacitor is formed from two metal plates with an insulator between them, as illustrated in Fig. 3.1. The potential difference across the plates is $V$. Fig. 3.2 shows how the magnitude of the charge $Q$ on one plate varies with $V$.

May/June 2011

As shown in Fig. 6.1, an uncharged capacitor is arranged in series with a battery, a switch and a resistor. The battery has an e.m.f. $9.0\,\text{V}$ and negligible internal resistance. The capacitor has capacitance $4700\,\mu\text{F}$. The switch is closed at $t = 0$. From $t = 0$ to $t = 4.0\,\text{s}$, a charge of $22\,\text{mC}$ passes through the resistor.

May/June 2014

As illustrated in Fig. 6.1, an initially uncharged capacitor is placed in series with a battery, a switch and a resistor. The battery has e.m.f. $9.0\,\text{V}$ and negligible internal resistance. The capacitance of the capacitor is $4700\,\mu\text{F}$. The switch is closed at time $t = 0$. Over the interval from $t = 0$ to $t = 4.0\,\text{s}$, the charge that flows through the resistor is $22\,\text{mC}$.

May/June 2014

Figure 7.1 shows a capacitor formed from two parallel metal plates with an insulator in between.

May/June 2017

In Fig. 5.1, capacitors A and B are placed in the circuit shown. Capacitor A has capacitance $C$ and capacitor B has capacitance $3C$. The cell has electromotive force (e.m.f.) $V$. The two-way switch $S$ starts at position $X$, and capacitor B is initially uncharged.

May/June 2023

Two capacitors X and Y are joined in series to a power supply of voltage $V$, as shown in Fig. 6.1. Capacitor X has capacitance $C_X$ and capacitor Y has capacitance $C_Y$.

May/June 2024

State the meaning of electric potential at a point.

Oct/Nov 2010

Define capacitance of a parallel-plate capacitor.

Oct/Nov 2024