A parcel-sorting machine uses an electromagnet to move an iron armature attached to a gate. A spring pulls the gate towards the straight-on position.
The gate diverts a parcel when the magnetic force on the armature is greater than 0.30 N.
The table shows data for two current settings.
| Setting | Current through electromagnet in A | Magnetic force on armature in N |
|---|---|---|
| A | 0.80 | 0.18 |
| B | 1.60 | 0.36 |
Explain why setting B, rather than setting A, should be used to divert a parcel.
Explain what happens to the gate when the controller switches off the current after the parcel has passed.
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.