# Describe how electricity generated by wind turbines reaches homes, including the role of transformers in the National Grid.

> OCR GCSE Physics A: Gateway Science (J249) — P6.1 Energy resources · Describe · 4 marks

> A wind farm is built in a remote area of Scotland. The electricity it generates must be transported hundreds of kilometres to homes in cities.

## Mark scheme (4 marks)

1. Electricity is transported along power cables at very high voltage (and low current)
2. A step-up transformer increases the potential difference (voltage) from the wind farm before transmission
3. Transmitting at high voltage reduces the current, which reduces the energy lost as heat in the power cables
4. A step-down transformer reduces the potential difference to a safer, lower voltage for domestic use

## Key terms

- [National Grid](https://www.gradenine.co.uk/glossary/national-grid)

## Related

- [Revision notes for OCR GCSE Physics A: Gateway Science (J249)](https://www.gradenine.co.uk/learn)
- [How to answer "Describe" questions](https://www.gradenine.co.uk/tools/command-word-cheatsheet)
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Source: [GradeNine](https://www.gradenine.co.uk/q/describe-how-electricity-generated-by-wind-d38eaa67) · Published by Druglandscape Ltd.