Magnetism and Electromagnetism

This unit covers magnets and magnetic fields, electromagnets, the motor effect, and for Triple students the generator effect, transformers, loudspeakers and microphones.

Field patterns need drawing accurately, with arrows running from north to south and correct spacing to show field strength. The motor effect requires Fleming's left hand rule, which rewards practising physically rather than trying to memorise it as a diagram — first finger field, second finger current, thumb motion. Students most often lose marks by confusing the left and right hand rules, and by describing a field without indicating direction. The factors affecting the strength of an electromagnet are examined regularly and expect specific answers: more turns, greater current, and an iron core.