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Physics Paper 1 · P2 · Lesson 2.3

Voltage and meters

Keep current through and voltage across separate.

Key ideas1 of 3

Voltage is potential difference

The exam term is potential difference (pd); voltage means the same thing. It is measured in volts (V). It tells us how much energy is transferred for each coulomb of charge.

At a potential difference of 3 volts, each coulomb transfers 3 joules of energy.

For example, 3 V means 3 joules transferred per coulomb.

Next: Resistance: making current smaller →
Topic resources and sources

Daily 5 · Exam practice · Extra calculation practice · A4 revision sheet

Start with lessons 2.1–2.6 for the circuit basics. Lesson 2.15 offers extra calculation practice. The P2 specification content is shared by Foundation and Higher Tier; extra practice is not Higher Tier-only.

AQA Combined Science Trilogy specification · 6.2.1.3. Original notes, questions and diagrams. Circuit animations are simplified; motion is deliberately slowed. Measurements and example values are illustrative. All practical circuits use suitable supervised low-voltage apparatus.

Photographs: Photograph of the inside of a UK plug by Alby Reid, Public domain, released by the copyright holder; Electricity pylons near Grafham Water by Mat Fascione, CC BY-SA 2.0; Photoresistor 2 by oomlout, CC BY-SA 2.0. Images displayed without cropping or alteration.