A battery charging unit contains a straight copper busbar carrying a steady current. A magnetic field probe is moved directly away from the busbar without changing the current.
Which statement describes the magnetic field at the probe after it is moved?
The field has the same strength but its direction is reversed.
The field has the same strength because the current is unchanged.
The field is stronger because the probe is further from the busbar.
The field is weaker because the probe is further from the busbar.
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.