Which of the following methods can be used to demagnetise a permanent bar magnet?
Hammering it repeatedly while it is aligned in an East-West direction
Placing it inside a plastic tube aligned in a North-South direction
Submerging it in cold, salty water for several hours
Connecting both of its ends directly to a low-voltage d.c. power supply
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.