A manufacturer is testing two samples for use as the core of a relay. One sample is iron and the other is steel.
Each sample is placed inside the same coil. Equal-sized steel clips are brought to one end of the sample while the coil carries a current. The current is then switched off, and the number of clips still held is recorded.
| Sample | Clips picked up while current flows | Clips still held after current is switched off |
|---|---|---|
| X | 10 | 1 |
| Y | 8 | 7 |
Which option gives both the identities of the samples and the better choice of core for the relay?
Sample X is iron and sample Y is steel; sample Y should be used as the relay core.
Sample X is steel and sample Y is iron; sample Y should be used as the relay core.
Sample X is iron and sample Y is steel; sample X should be used as the relay core.
Sample X is steel and sample Y is iron; sample X should be used as the relay core.
70 exam-style questions on Edexcel GCSE Physics 12.1 Magnets and magnetic fields, covering 12.1.1 Magnetic poles, 12.1.2 Magnetic materials; permanent and induced magnets, 12.1.3 Magnetic fields, and 12.1.4 Plotting compasses and the Earth's magnetic field. Each one has a worked solution and a mark scheme showing where the marks go.