# A student has a battery, a fixed resistor, a variable resistor, a voltmeter and an ammeter. Describe how the student could use these components to investigate how the current through the fixed resistor changes as the potential difference across it is altered. Include in your answer how each measuring instrument should be connected and what the student should do to vary the readings.

> WJEC A-Level Physics (Wales) — 2.2 DC circuits · Describe · 5 marks

## Mark scheme (5 marks)

1. The ammeter is connected in series with the fixed resistor
2. The voltmeter is connected in parallel across the fixed resistor
3. The variable resistor is connected in series in the circuit
4. Adjusting the variable resistor changes the current / potential difference in the circuit
5. Record the ammeter and voltmeter readings for several different settings of the variable resistor

## Key terms

- [ammeter](https://www.gradenine.co.uk/glossary/ammeter)
- [voltmeter](https://www.gradenine.co.uk/glossary/voltmeter)
- [variable resistor](https://www.gradenine.co.uk/glossary/variable-resistor)
- [potential difference](https://www.gradenine.co.uk/glossary/potential-difference)
- [current](https://www.gradenine.co.uk/glossary/current)

## Related

- [Revision notes for WJEC A-Level Physics (Wales)](https://www.gradenine.co.uk/learn)
- [How to answer "Describe" 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/a-student-has-a-battery-a-9c9eb78b) · Published by Druglandscape Ltd.