Physics 9702 · AS & A Level
Capacitors and capacitance
35 practice questions on Capacitors and capacitance, with worked solutions and instant marking.
Define capacitance.
Feb/March 2016
What is the capacitance of a parallel-plate capacitor?
Feb/March 2019
State two roles that capacitors play in electrical circuits.
May/June 2010
State two uses of capacitors in electrical circuits.
May/June 2010
An insulated metal sphere with radius $R$ is placed in a vacuum. Its charge $q$ may be treated as a point charge located at the centre of the sphere.
May/June 2013
A student assembles the circuit in Fig. 7.1 in order to measure the charge on a capacitor C for a range of potential differences across the capacitor. Fig. 7.2 shows how the charge Q stored on the capacitor varies with potential difference V.
May/June 2016
State two uses of capacitors in electrical circuits, apart from smoothing direct current.
May/June 2016
A student arranges the circuit in Fig. 7.1 in order to measure the charge on capacitor $C$ for a range of potential differences across the capacitor. The way in which the charge $Q$ stored on the capacitor changes with potential difference $V$ is shown in Fig. 7.2.
May/June 2016
Explain the meaning of the capacitance of a parallel plate capacitor.
May/June 2018
Explain what the capacitance of a parallel plate capacitor means.
May/June 2018
Explain the meaning of the capacitance of a parallel plate capacitor.
May/June 2018
State two separate functions that capacitors perform in electrical circuits.
May/June 2019
State two distinct functions that capacitors perform in electrical circuits.
May/June 2019
State what the capacitance of a parallel plate capacitor means.
May/June 2021
Explain how the plates may function as a capacitor.
May/June 2021
State what the capacitance of a parallel plate capacitor means.
May/June 2021
What does the capacitance of a parallel plate capacitor mean?
May/June 2022
Define capacitance in words.
Oct/Nov 2010
Define capacitance in words.
Oct/Nov 2010
State two uses of capacitors in electrical circuits.
Oct/Nov 2011
Define capacitance as the charge stored per unit potential difference.
Oct/Nov 2012
Define capacitance in this context.
Oct/Nov 2012
State two roles that capacitors play in electrical circuits.
Oct/Nov 2013
Three capacitors, each with capacitance $48\,\mu\text{F}$, are arranged as shown in Fig. 6.1.
Oct/Nov 2014
Define the term capacitance.
Oct/Nov 2016
Capacitors P and Q, each with capacitance $C$, are linked in series to a battery of e.m.f. $9.0\,\text{V}$, as illustrated in Fig. 6.1. A switch $S$ is used to place either a third capacitor $T$, which also has capacitance $C$, or a resistor $R$, in parallel with capacitor P.
Oct/Nov 2017
Two capacitors P and Q, each with capacitance $C$, are arranged in series with a battery of e.m.f. $9.0\,\text{V}$, as illustrated in Fig. 6.1. Switch S allows either a third capacitor T, also having capacitance $C$, or a resistor R, to be connected in parallel with capacitor P.
Oct/Nov 2017
Define what is meant by the capacitance of a parallel plate capacitor.
Oct/Nov 2020
Define what is meant by the capacitance of a parallel plate capacitor.
Oct/Nov 2020
Define the capacitance of a parallel plate capacitor in terms of charge stored and potential difference.
Oct/Nov 2020
The capacitor shown in Fig. 6.1 has two parallel metal plates with air between them, separated by a variable gap $x$. The capacitance $C$ varies inversely with $x$. A supply charges the capacitor so that a potential difference (p.d.) $V$ exists across the plates.
Oct/Nov 2021
A capacitor is formed from two parallel metal plates, with air between them, separated by a variable distance $x$, as shown in Fig. 6.1. Since $C$ is inversely proportional to $x$, the capacitor is charged by a supply so that the plates have a potential difference (p.d.) $V$. State expressions, in terms of $C$ and $V$, for the charge $Q$ on one plate and for the energy $E$ stored in the capacitor.
Oct/Nov 2021
Two parallel plate capacitors $C_1$ and $C_2$ are linked to a supply with potential difference (p.d.) $V_S$. They may be arranged either in series or in parallel. The supply delivers charge $Q_S$, and the plates of the two capacitors end up with charges $Q_1$ and $Q_2$ respectively. The p.d.s across the capacitor plates are $V_1$ and $V_2$ respectively.
Oct/Nov 2025
An isolated conducting sphere in a vacuum has a capacitance of $69\,\text{pF}$, and the sphere carries a charge of $+83\,\text{pC}$.
Oct/Nov 2025
Two parallel-plate capacitors $C_1$ and $C_2$ are attached to a supply with potential difference (p.d.) $V_S$. They can be arranged either in series or in parallel. The supply delivers charge $Q_S$, while the plates of the two capacitors gain charges $Q_1$ and $Q_2$ respectively. The p.d.s across the capacitor plates are $V_1$ and $V_2$ respectively. Complete Table 6.1 to show the relationships between $Q_S$, $Q_1$ and $Q_2$, and between $V_S$, $V_1$ and $V_2$, for series and parallel connections of the capacitors to the supply.
Oct/Nov 2025