An electromagnetic actuator moves a sliding pin in a packaging machine. A straight section of conductor carries a current at right angles to a magnetic field. The current and the magnetic field can be reversed independently.
The table shows the results from four settings. All other factors were kept the same.
| Setting | Current direction compared with setting A | Magnetic field direction compared with setting A | Direction of force on the conductor |
|---|---|---|---|
| A | same | same | towards the pin |
| B | reversed | same | away from the pin |
| C | same | reversed | away from the pin |
| D | not recorded | not recorded | towards the pin |
An engineer concludes that in setting D both the current and the magnetic field must have been reversed.
Evaluate the engineer's conclusion.
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.