# Explain how a capacitor stores energy and describe the factors that affect the energy stored in a capacitor.

> AQA A-Level Physics (7408) — 3.7.4 Capacitance · Explain · 5 marks

## Mark scheme (5 marks)

1. A capacitor stores charge on its plates (equal and opposite charges on each plate)
2. The separated charges create a potential difference / electric field between the plates, and energy is stored in this electric field
3. Greater capacitance means more energy is stored (for the same potential difference)
4. Greater potential difference means more energy is stored
5. Energy stored is proportional to the square of the potential difference (energy increases rapidly as pd increases)

## Key terms

- [energy stored](https://www.gradenine.co.uk/glossary/energy-stored)

## Related

- [Revision notes for AQA A-Level Physics (7408)](https://www.gradenine.co.uk/learn)
- [How to answer "Explain" questions](https://www.gradenine.co.uk/tools/command-word-cheatsheet)
- [Practice this with AI marking (free)](https://www.gradenine.co.uk/start)

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Source: [GradeNine](https://www.gradenine.co.uk/q/explain-how-a-capacitor-stores-energy-10973484) · Published by Druglandscape Ltd.