# A set of fairy lights is wired in series. When one bulb breaks and stops conducting, all the other bulbs go out. A student suggests that rewiring the fairy lights in parallel would solve this problem. Explain why the student's suggestion is correct.

> OCR GCSE Physics A: Gateway Science (J249) — P3.2 Simple circuits · Explain · 4 marks

> Fairy lights are commonly used as decorative lighting. Older sets were wired in series, meaning a single broken bulb caused the entire set to stop working.

## Mark scheme (4 marks)

1. In a series circuit there is only one path for current to flow
2. A broken bulb in series creates a gap/break, so no current flows anywhere in the circuit
3. In a parallel circuit each bulb has its own separate path/branch for current
4. If one bulb breaks in parallel, current can still flow through the other branches, so the remaining bulbs stay on

## Related

- [Revision notes for OCR GCSE Physics A: Gateway Science (J249)](https://www.gradenine.co.uk/learn)
- [How to answer "Explain" questions](https://www.gradenine.co.uk/tools/command-word-cheatsheet)
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