An engineer tests two prototype electrical supplies for an electronic control unit that contains integrated circuits. The voltage between the output terminals is measured at equal time intervals. The same output terminal is used as the reference for every measurement.
| successive measurement | 1 | 2 | 3 | 4 | 5 | 6 |
|---|---|---|---|---|---|---|
| voltage of supply X / V | +3.0 | +5.0 | +2.0 | +4.0 | +3.0 | +2.0 |
| voltage of supply Y / V | +6.0 | +2.0 | -4.0 | -6.0 | -2.0 | +6.0 |
The control unit is to be connected directly to one of the supplies.
Explain which supply should be used for the control unit.
81 exam-style questions on Edexcel GCSE Physics 10.4 Mains electricity, covering 10.4.1 Direct and alternating current, 10.4.2 Live, neutral and earth wires; safety, 10.4.3 Mains wire potential differences and dangers, and 10.4.4 Power ratings and energy use. Each one has a worked solution and a mark scheme showing where the marks go.