A machine polishes two initially neutral insulating discs using two separate, initially neutral dry pads. Disc A gains electrons from pad C. In the other part of the machine, disc B loses electrons to pad D. Disc A and pad D are removed from the machine and brought close together without touching.
Which statement describes the resulting electrostatic interaction?
Disc A and pad D repel because both have gained electrons and become negatively charged.
Disc A and pad D attract because A becomes positive while D becomes negative.
Disc A and pad D attract because both have gained electrons and become negatively charged.
Disc A and pad D repel because A becomes negative while D becomes positive.
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.