Which action describes a method for demagnetising a magnetised steel bar?
Stroke the bar repeatedly in one direction with the same pole of a strong permanent magnet.
Place the bar inside a solenoid connected to a direct current (d.c.) supply.
Place the bar inside a solenoid connected to an alternating current (a.c.) supply and slowly withdraw it.
Place the bar next to a magnet and tap it repeatedly with a hammer.
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.