A transformer is used to connect a smart speaker to the mains electricity supply. The input voltage to the transformer is 230 V. The output voltage from the transformer is 12.0 V. The output current from the transformer is 1.15 A. The transformer is 100% efficient. Calculate the input current to the transformer. Use the equation:
input current×input voltage=output current×output voltage \text{input current} \times \text{input voltage} = \text{output current} \times \text{output voltage} input current×input voltage=output current×output voltage28 exam-style questions on Edexcel GCSE Physics 13.2 Transformers and the National Grid. Each one has a worked solution and a mark scheme showing where the marks go.