A 100% efficient transformer supplies an electromagnet that moves a sorting gate. The primary coil is connected to a 230 V alternating supply.
While the gate is stationary, the primary current is 0.30 A. During a 20 s movement, the secondary circuit transfers 690 J more energy than it would while the gate was stationary.
Calculate the primary current while the gate is moving.
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.