A technician tests four transformers. For each transformer, the table gives the potential difference and current in each coil.
| Transformer | Primary potential difference / V\mathrm{V}V | Primary current / A\mathrm{A}A | Secondary potential difference / V\mathrm{V}V | Secondary current / A\mathrm{A}A |
|---|---|---|---|---|
| W | 240 | 0.10 | 12 | 1.0 |
| X | 120 | 0.20 | 6.0 | 4.0 |
| Y | 240 | 0.20 | 24 | 1.0 |
| Z | 120 | 0.10 | 12 | 2.0 |
Which transformer has results consistent with 100% efficiency?
Transformer W
Transformer X
Transformer Y
Transformer Z
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.