Four ideal step-down transformers are being evaluated for use in a spot-welding machine that requires a high secondary current. The primary coil of each transformer is connected to a 230 V AC mains supply protected by a 13.0 A fuse.
The table below shows the number of turns on the primary and secondary coils of each transformer:
| Transformer | Primary turns (NpN_pNp) | Secondary turns (NsN_sNs) |
|---|---|---|
| P | 400 | 100 |
| Q | 600 | 50 |
| R | 1200 | 40 |
| S | 800 | 80 |
Which transformer can deliver the largest secondary current before the fuse on the primary supply blows?
Transformer P
Transformer Q
Transformer R
Transformer S
34 exam-style questions on OCR A A Level Physics Electromagnetism, covering Magnetic fields, Motion of charged particles, and Electromagnetism. Each one has a worked solution and a mark scheme showing where the marks go.