A transformer is used to supply a set of garden lights.
The potential difference across the primary coil is 230 V and the current in the primary coil is 2.0 A.
The potential difference across the secondary coil is 11.5 V.
The transformer is 100% efficient.
Calculate the current in the secondary coil.
Use the equation
VP×IP=VS×ISV_P \times I_P = V_S \times I_SVP×IP=VS×IS
A real transformer is only 95% efficient.
Calculate the useful power output of the real transformer when the power input is 460 W.
Suggest what happens to the energy that is not usefully transferred by the real transformer.
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.