A neutral insulating rod is rubbed with a neutral cloth. The rod gains a charge of −8 nC-8\ \mathrm{nC}−8 nC. No charge passes to the surroundings. Which statement gives the charge on the cloth and explains how it formed?
+8 nC+8\ \mathrm{nC}+8 nC, because electrons left the cloth
−8 nC-8\ \mathrm{nC}−8 nC, because protons left the cloth
−8 nC-8\ \mathrm{nC}−8 nC, because electrons entered the cloth
+8 nC+8\ \mathrm{nC}+8 nC, because protons entered the cloth
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.