A transformer supplies a motor that opens a retractable roof panel. During one operation, the motor transfers 21.6 kJ of energy in 3.0 minutes.
The transformer wastes no energy. Its primary coil has 800 turns. Its secondary coil has 80 turns and a potential difference of 24 V.
Calculate the primary current.
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.