# A student sets up a series circuit containing a battery, a fixed resistor, and a light-emitting diode (LED). The student then reverses the LED so that it faces the opposite direction. Explain what happens to the current in the circuit when the LED is reversed, and why this occurs.

> Edexcel GCSE Physics (1PH0) — 10.1 Electricity and circuits · Explain · 4 marks

## Mark scheme (4 marks)

1. The current (in the circuit) drops to zero / no current flows when the LED is reversed
2. A diode / LED only allows current to flow in one (forward) direction
3. In the reverse direction the LED has a very high / very large resistance
4. Because resistance is very high, (the opposition to current flow is so great that) current cannot flow / is prevented from flowing through the circuit

## Key terms

- [light-emitting diode](https://www.gradenine.co.uk/glossary/light-emitting-diode)
- [current](https://www.gradenine.co.uk/glossary/current)
- [series circuit](https://www.gradenine.co.uk/glossary/series-circuit)
- [diode](https://www.gradenine.co.uk/glossary/diode)

## Related

- [Revision notes for Edexcel GCSE Physics (1PH0)](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-sets-up-a-series-82d35538) · Published by Druglandscape Ltd.