A food factory blows powdered sugar through an insulating duct into an enclosed metal hopper. The hopper is connected to earth.
The maximum potential difference between the duct and the hopper is measured at two transfer rates.
| Transfer rate (kg/s) | Maximum potential difference (kV) |
|---|---|
| 1.0 | 3.0 |
| 3.0 | 8.0 |
An engineer proposes attaching one end of a metal cable to the outside of the insulating duct and the other end to earth before transfer starts. The duct would not otherwise be changed.
Use the measurements to explain how changing the transfer rate affects the electrostatic risk. Evaluate the engineer's proposal and suggest one effective precaution.
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.