# Explain what happens to the current through each component and the total current from the battery when an additional resistor is added in parallel to an existing resistor already connected to a battery.

> AQA A-Level Physics (7408) — 3.5.1 Current Electricity · Explain · 5 marks

> A simple circuit contains a battery connected to a single resistor. A second, identical resistor is then connected in parallel with the first.

## Mark scheme (5 marks)

1. The potential difference across each resistor remains the same (equal to the battery voltage)
2. The current through the original resistor is unchanged
3. The second (new) resistor also has a current flowing through it
4. The total current from the battery increases because the total current equals the sum of the currents in each branch
5. The total resistance of the circuit decreases (is less than the resistance of either individual resistor)

## Key terms

- [parallel](https://www.gradenine.co.uk/glossary/parallel)
- [current](https://www.gradenine.co.uk/glossary/current)
- [total current](https://www.gradenine.co.uk/glossary/total-current)

## 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-what-happens-to-the-current-38dff687) · Published by Druglandscape Ltd.