An AC mains power adapter for a gaming device contains a step-down transformer.
The number of turns on the primary coil of a step-down transformer is:
This transformer is designed to reduce the voltage from 240 V to 9 V.
The primary current is 0.15 A.
State the equation linking primary voltage, primary current, secondary voltage, and secondary current for a transformer.
Calculate the secondary current, assuming that the transformer is 100% efficient.
A user notices that the power adapter becomes warm when it is working. Suggest how this will affect the power output of the transformer compared to its power input.
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.