A dynamo uses a split-ring commutator to generate direct current. The diagram shows the internal parts of a dynamo connected to a resistor in a complete circuit:
The coil is rotated. Explain why a direct current is induced in the external circuit.
Describe the shape of a graph showing how the potential difference generated across the resistor varies with time for two complete revolutions of the dynamo coil.
The resistor is disconnected from the dynamo. Explain why the dynamo's coil becomes much easier to turn.
Induced potential, transformers and the National Grid (physics only) (HT only) Questions
Practise AQA GCSE Physics Induced potential, transformers and the National Grid (physics only) (HT only) with exam-style questions for Foundation and Higher tier. 15 questions covering Induced potential (HT only), Uses of the generator effect (HT only), Microphones (HT only), and Transformers (HT only), matched to the AQA GCSE Physics (8463) specification and written in Paper 1 and Paper 2 style. Every question includes a full worked solution and mark scheme, so you can see where marks are awarded rather than just whether you got the answer right.