A student cleans a plastic shelf by wiping it with a dry cloth.
The shelf becomes negatively charged.
Soon afterwards, dust collects on the shelf.
Explain how wiping the shelf causes it to become negatively charged.
The dust particles are uncharged.
Explain why the dust particles are attracted to the shelf.
The student wipes the shelf with a damp cloth instead.
Much less dust collects on the shelf.
Suggest why.
91 exam-style questions on Edexcel GCSE Physics 11.1 Charging by friction, covering 11.1.1 Charging insulators by friction, 11.1.2 Forces between charges, 11.1.3 Electrostatic phenomena, and 11.1.4 Earthing and removing charge. Each one has a worked solution and a mark scheme showing where the marks go.