A generator in a wave-energy device has a coil rotating between the poles of a magnet. Each end of the coil is connected to a separate slip ring. During maintenance, the slip rings are replaced by a split-ring commutator. The coil, magnet and rotational speed are unchanged.
What is the effect of this change on the output potential difference measured across the brushes?
The output changes from direct to alternating because the connections to the external circuit are swapped every half-turn.
The output becomes a constant direct potential difference because the commutator makes the coil cut field lines at a constant rate.
The output changes from alternating to direct because the connections to the external circuit are swapped every half-turn.
The output remains alternating because the potential difference induced in the coil still reverses every half-turn.
96 exam-style questions on AQA GCSE Physics 7.3 Induced potential, transformers and the National Grid (HT only), covering 7.3.1 Induced potential (HT only), 7.3.2 Uses of the generator effect (HT only), 7.3.3 Microphones (HT only), and 7.3.4 Transformers (HT only). Each one has a worked solution and a mark scheme showing where the marks go.