A visitor listens to a museum audio guide through a moving-coil earpiece. The earpiece has a small diaphragm attached to a coil in the field of a permanent magnet. The variations in the alternating current become larger, but their frequency stays the same.
How does the sound heard by the visitor change?
The sound becomes quieter because the force acting on the diaphragm becomes smaller
The sound stays unchanged because the frequency of the current stays the same
The sound becomes louder because the diaphragm moves further backwards and forwards
The sound becomes higher in pitch because the diaphragm moves further backwards and forwards
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.