A bar magnet is held with its north pole pointing downwards.
Some small iron nails hang in a chain below the magnet. Only the top nail touches the magnet.
Explain why the second nail is attracted to the top nail.
The bar magnet is lifted away from the top nail.
Describe and explain what happens to the chain of nails.
A student says:
'If I turn the magnet round so that its south pole points downwards, the nails will be repelled.'
Explain why the student is wrong.
44 exam-style questions on OCR GCSE Physics 4.1 Magnets and magnetic fields, covering 4.1.1 Magnetic poles, attraction and repulsion, 4.1.2 Permanent and induced magnets, 4.1.3 The magnetic field of a magnet, 4.1.4 Compasses and the Earth's magnetic field, 4.1.5 The magnetic field around a current-carrying wire, 4.1.6 Field strength, current and distance, and 4.1.7 Solenoids and electromagnets. Each one has a worked solution and a mark scheme showing where the marks go.