# Voltmeter

## Key Stage 3

### Meaning

A picture showing an analogue voltmeter.

A voltmeter is a measuring device used to measure the potential difference between two points in a circuit.

Voltmeters are added in parallel to components in a circuit to find the potential difference between two points.
An ideal voltmeter has infinite resistance because otherwise adding an voltmeter to a circuit would change the Potential Difference between two points.
Voltmeters can be analogue with a needle pointing to numbers on a dial or it can be digital with a number display.
 A voltmeter placed in parallel with a bulb.

## Key Stage 4

### Meaning

A voltmeter is a measuring device used to measure the potential difference between two points in a circuit.

Voltmeters are added in parallel to components in a circuit to find the potential difference between two points.
An ideal voltmeter has infinite resistance because otherwise adding an voltmeter to a circuit would change the potential difference between the two points.
Voltmeters can be analogue with a needle pointing to numbers on a dial or it can be digital with a number display.
 To measure the potential difference across bulb 1 the voltmeter must be placed in parallel with bulb 1. To measure the potential difference across bulb 2 the voltmeter must be placed in parallel with bulb 2.
 To measure the potential difference across bulb 1 the voltmeter must be placed in parallel with bulb 1. To measure the potential difference across bulb 2 the voltmeter must be placed in parallel with bulb 2. In this case both voltmeters will give the same measurement because the components themselves are in parallel.

### References

#### AQA

Voltmeter, pages 52-3, 56, GCSE Physics; Student Book, Collins, AQA
Voltmeters, page 239, GCSE Combined Science; The Revision Guide, CGP, AQA
Voltmeters, page 41, GCSE Physics, Hodder, AQA
Voltmeters, page 52, GCSE Physics; Third Edition, Oxford University Press, AQA
Voltmeters, pages 25, 106, GCSE Physics; The Revision Guide, CGP, AQA
Voltmeters, pages 293, 296, GCSE Combined Science Trilogy 1, Hodder, AQA
Voltmeters, pages 60, 61, 235, GCSE Combined Science Trilogy; Physics, CGP, AQA
Voltmeters, pages 62, 63, 331, GCSE Physics; The Complete 9-1 Course for AQA, CGP, AQA
Voltmeters; calibration of, page 316-17, GCSE Combined Science Trilogy 1, Hodder, AQA
Voltmeters; calibration of, pages 64-5, GCSE Physics, Hodder, AQA
Voltmeters; circuit symbol, page 38, GCSE Physics, Hodder, AQA

#### Edexcel

Voltmeters, page 143, GCSE Physics, Pearson Edexcel
Voltmeters, pages 186, 210, GCSE Combined Science; The Revision Guide, CGP, Edexcel
Voltmeters, pages 220, 338, 339, GCSE Physics, CGP, Edexcel
Voltmeters, pages 73, 106, GCSE Physics; The Revision Guide, CGP, Edexcel

#### OCR

Voltmeters, pages 101-103, 259, Gateway GCSE Physics, Oxford, OCR
Voltmeters, pages 178, 224, Gateway GCSE Combined Science; The Revision Guide, CGP, OCR
Voltmeters, pages 45, 49, 105, Gateway GCSE Physics; The Revision Guide, CGP, OCR