# A torch uses a 6 V battery and contains a filament lamp connected in series with two identical resistors. The potential difference across each resistor is 1.5 V. Explain how the potential differences across the lamp and the two resistors are related to the battery voltage, and state the potential difference across the lamp.

> Pearson Edexcel International GCSE Physics (4PH1) — 2.2 Energy and voltage in circuits · Explain · 4 marks

> A torch contains a 6 V battery connected in series with a filament lamp and two identical resistors. The potential difference across each resistor is 1.5 V.

## Mark scheme (4 marks)

1. In a series circuit, the potential differences across the components add up to / are shared to equal the total potential difference of the supply (6 V).
2. The total potential difference across both resistors is 1.5 + 1.5 = 3 V.
3. The potential difference across the lamp is 6 − 3 = 3 V.
4. The lamp has a greater potential difference across it than each individual resistor because it has a greater resistance (in a series circuit, a component with greater resistance has a larger share of the potential difference).

## Key terms

- [potential difference](https://www.gradenine.co.uk/glossary/potential-difference)
- [series](https://www.gradenine.co.uk/glossary/series)

## Related

- [Revision notes for Pearson Edexcel International GCSE Physics (4PH1)](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-torch-uses-a-6-v-477e6bcf) · Published by Druglandscape Ltd.