A student investigates the magnetic properties of different materials used as cores in an electromagnet. She wraps a coil of wire around a core made of a test material, connects the coil to a d.c. power supply, and observes how many steel paperclips are picked up when the power supply is switched on. She then switches the power supply off and counts how many paperclips remain attached to the core.
She repeats this experiment with four different core materials, labelled P, Q, R, and S. The results are shown in the table:
| Core material | Paperclips picked up when the power supply is turned ON | Paperclips remaining attached when the power supply is turned OFF |
|---|---|---|
| P | 0 | 0 |
| Q | 16 | 13 |
| R | 18 | 0 |
| S | 4 | 1 |
Which core material is made of soft iron?
P
Q
R
S
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.