A workshop sprays paint onto metal mesh guards. Each guard is earthed. The spray flow rate and the amount of paint released are kept the same. The table shows the spray-cloud width and the mass of paint deposited on the rear of a guard at different charging-unit settings.
| Charging-unit setting | Spray-cloud width (cm) | Paint deposited on rear (g) |
|---|---|---|
| High | 34 | 12 |
| Medium | 27 | 8 |
| Low | 21 | 4 |
Using the results, explain what you would expect when the charging unit is switched off.
80 exam-style questions on Edexcel GCSE Physics 11.2 Uses, dangers and electric fields, covering 11.2.1 Uses of electrostatic charge, 11.2.2 Dangers of sparking, 11.2.3 Electric fields, and 11.2.4 Electric fields and static electricity. Each one has a worked solution and a mark scheme showing where the marks go.