A resistance-welding machine uses a transformer that is 100% efficient. The transformer decreases the potential difference supplied to the welding electrodes. The secondary circuit is complete.
Which statement explains how the transformer provides the welding electrodes with a high current?
The iron core provides additional electrical power to the secondary circuit.
The lower secondary potential difference gives a larger secondary current for the same power.
The secondary coil has more turns than the primary coil, so it carries a larger current.
The changing magnetic field transfers the primary current directly into the secondary circuit.
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.