A technician connects the primary coil of a demountable transformer to a low-voltage alternating supply. Both coils are initially fitted on the same soft iron core, and a voltmeter is connected across the secondary coil.
The technician lifts the secondary coil off the core and moves it away from the primary coil. The voltmeter reading falls to almost zero.
Explain why the voltmeter reading falls.
108 exam-style questions on Edexcel GCSE Physics 13.2 Transformers and the National Grid, covering 13.2.1 Transformers and induction, 13.2.2 The transformer turns-ratio equation, 13.2.3 The National Grid, 13.2.4 The transformer power equation, and 13.2.5 Advantages of high-voltage transmission. Each one has a worked solution and a mark scheme showing where the marks go.