# A lorry carrying fuel through a dry desert region can build up a large static charge as it travels. Before connecting a fuel pipe to a storage tank, the driver attaches a metal wire between the lorry and the tank. Explain why this is necessary to prevent a spark.

> OCR GCSE Physics A: Gateway Science (J249) — P3.1 Static and charge · Explain · 4 marks

> Fuel tanker lorries can accumulate static charge whilst travelling due to friction between tyres and the road surface, and between fuel and the inside of the tank. A spark near flammable fuel can be extremely dangerous.

## Mark scheme (4 marks)

1. Friction causes electrons to transfer, building up charge on the lorry
2. The lorry and tank may be at different electrical potentials / have different charges
3. The metal wire allows charge / electrons to flow between the lorry and tank, equalising their charge
4. Without the wire, charge could discharge suddenly across the gap as a spark, which could ignite the fuel

## Key terms

- [static charge](https://www.gradenine.co.uk/glossary/static-charge)
- [spark](https://www.gradenine.co.uk/glossary/spark)

## 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)
- [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-lorry-carrying-fuel-through-a-5ac770be) · Published by Druglandscape Ltd.