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Separate Physics · Paper 2 · Higher Tier only · P7

Higher: alternators, dynamos and output graphs

Key ideas1 of 3

Rotation changes the induced direction

Turning a coil in a magnetic field induces a potential difference because its sides move through the field. As each side changes its direction of motion relative to the field during a turn, the induced potential difference changes. Mechanical work drives the rotation. An alternator uses slip rings and brushes to keep each end of the coil connected to the same external terminal.

Rotating coil between fixed north and south poles with two separate slip rings and stationary brushes.

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Practice, downloads and sources

Daily 5 · Exam practice · Revision sheet ↓

Higher Tier only · P7. Use alongside the shared P7 lessons.

AQA GCSE Physics 8463 · 4.7.3.2. Original notes, questions and diagrams. Models are simplified; teaching data are illustrative.