# A student connects two resistors in a parallel circuit. Explain why the total resistance of two resistors connected in parallel is less than the resistance of either individual resistor.

> OCR A-Level Physics A (H556) — 3.1 Motion · Explain · 5 marks

> A student is building a circuit for a school project. They notice that when they connect two resistors in parallel, the total resistance of the combination is lower than the resistance of either resistor on its own. The student finds this surprising, as they expected adding more components to always increase resistance.

## Mark scheme (5 marks)

1. In a parallel circuit, the current splits and takes more than one path (branch)
2. Only some of the total charge flows through each individual resistor / branch
3. This means there is less overall opposition to the flow of charge compared to a single resistor
4. The total resistance is less than the smallest individual resistance in the parallel combination
5. Contrast with series: in series all charge must pass through every resistor, so resistances add up and total resistance increases

## Key terms

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

## Related

- [Revision notes for OCR A-Level Physics A (H556)](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/a-student-connects-two-resistors-in-68807355) · Published by Druglandscape Ltd.