An industrial step-up transformer is used in a neon sign power supply to convert the mains electrical supply to a higher voltage.
Compare the number of turns on the primary coil of a step-up transformer with the number of turns on its secondary coil.
This transformer is designed to increase the voltage from 230 V230\text{ V}230 V to 4.6 kV4.6\text{ kV}4.6 kV. The secondary current is 15 mA15\text{ mA}15 mA.
(i) State the equation linking primary voltage, primary current, secondary voltage, and secondary current for a transformer.
(ii) Calculate the primary current in the transformer, assuming the transformer is 100%100\%100% efficient.
An engineer notices that the transformer casing becomes warm during operation.
Suggest how this affects the electrical input to the transformer, assuming the secondary voltage and secondary current do not change.
20 exam-style questions on Edexcel IGCSE Physics Electromagnetic induction. Each one has a worked solution and a mark scheme showing where the marks go.