A force meter is used to pull a steel washer away from an iron plate. While a permanent magnet is close to the plate, the meter reads 0.80 N. The permanent magnet is then moved a long distance away. What happens to the force needed to pull the washer away?
It becomes much greater than 0.80 N because magnetic fields get stronger further from a magnet
It varies each time because induced magnetism does not produce fixed magnetic poles
It stays at 0.80 N because contact with the washer maintains the magnetism of the plate
It becomes much less than 0.80 N because the plate loses most or all of its induced magnetism
80 exam-style questions on AQA GCSE Physics 7.1 Permanent and induced magnetism, magnetic forces and fields, covering 7.1.1 Poles of a magnet and 7.1.2 Magnetic fields. Each one has a worked solution and a mark scheme showing where the marks go.