A student investigates how different core materials affect the strength and retention of magnetism in an electromagnet. She wraps a coil around a core made of a certain material, switches a d.c. power supply on, and counts how many iron pins are picked up. She then switches the power supply off and counts how many pins remain attached.
She repeats this procedure using four different core materials: A, B, C, and D. The results are recorded in the table below:
| Core | Pins picked up with the power supply ON | Pins picked up with the power supply OFF |
|---|---|---|
| A | 0 | 0 |
| B | 15 | 1 |
| C | 14 | 11 |
| D | 3 | 4 |
Which core is most likely made of steel?
Core A
Core B
Core C
Core D
169 exam-style questions on CIE IGCSE Physics Simple phenomena of magnetism, covering Simple phenomena of magnetism. Each one has a worked solution and a mark scheme showing where the marks go.