A straight heating wire in a foam-cutting tool carries a constant current. Point P is 4 cm from the wire and point Q is 1 cm from the wire. The magnetic field strength is measured first at P and then at Q. What happens to the magnetic field strength?
It is unchanged, because P and Q are both outside the wire
It increases, because the current in the wire is larger near Q
It increases, because Q is closer to the wire
It decreases, because the field spreads out from the wire
90 exam-style questions on AQA GCSE Physics 7.2 The motor effect, covering 7.2.1 Electromagnetism, 7.2.2 Fleming's left-hand rule (HT only), 7.2.3 Electric motors (HT only), and 7.2.4 Loudspeakers (HT only). Each one has a worked solution and a mark scheme showing where the marks go.