A step-down transformer supplies workshop equipment at a railway maintenance depot. Its primary coil is connected to a 6600 V alternating supply. The secondary coil provides 400 V and carries a current of 165 A. The transformer is 100% efficient.
An ammeter is connected in series with the primary coil.
Calculate the reading expected on the ammeter.
Use the equation
VP×IP=VS×ISV_P \times I_P = V_S \times I_SVP×IP=VS×IS
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.