A manufacturer sprays a solvent-based protective liquid onto metal mesh filters.
The nozzle points towards the near face of each filter. The opposite face is called the far face.
In each test, the sprayer releases 120 g of liquid. For the charged test, every droplet is positively charged and the metal filter is earthed.
| Spraying system | Mass deposited on near face / g | Mass deposited on far face / g | Mass not deposited on filter / g |
|---|---|---|---|
| uncharged | 48 | 12 | 60 |
| charged | 58 | 39 | 23 |
The liquid releases a flammable solvent vapour.
Explain why charging the droplets changes the distribution of liquid shown in the table.
A manager claims that charging the droplets prevents waste and makes the masses deposited on the two faces equal.
Evaluate this claim using the data in the table.
Explain how keeping the metal filter earthed reduces the risk of the solvent vapour catching fire.
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.