Workshop equipment receives power through a transformer that wastes no energy. When the input potential difference is 230 V, the transformer is designed to draw no more than 0.18 A.
One equipment bank at a time is supplied from the secondary. Every device operates at its rated power.
| Bank | Devices in the bank | Rated power of each device |
|---|---|---|
| A | three cooling fans | 12 W |
| B | five display units | 8.0 W |
| C | four water pumps | 10.5 W |
| D | six small motors | 7.5 W |
Which bank transfers the greatest total power without causing the input current to exceed its limit?
Bank A: three cooling fans
Bank D: six small motors
Bank C: four water pumps
Bank B: five display units
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.