# Explain how a positive test charge placed between two oppositely charged parallel plates experiences an electric force, and describe how the electric field between the plates differs from the electric field near an isolated point charge.

> AQA A-Level Physics (7408) — 3.7.3 Electric Fields · Explain · 5 marks

## Mark scheme (5 marks)

1. An electric field is a region where a charged object experiences a force
2. The positive test charge experiences a force in the direction of the electric field (from positive plate to negative plate)
3. The electric field between the parallel plates is uniform
4. The electric field near an isolated point charge is non-uniform / radial
5. The field strength near a point charge decreases as distance from the charge increases, whereas the uniform field between the plates stays constant

## Key terms

- [electric field](https://www.gradenine.co.uk/glossary/electric-field)
- [test charge](https://www.gradenine.co.uk/glossary/test-charge)
- [point charge](https://www.gradenine.co.uk/glossary/point-charge)

## 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)

---
Source: [GradeNine](https://www.gradenine.co.uk/q/explain-how-a-positive-test-charge-32b20f5f) · Published by Druglandscape Ltd.