A neutral rod is rubbed first with cloth P and then with cloth Q. During the first rubbing, 600 electrons move from P to the rod. During the second rubbing, 200 electrons move from the rod to Q. No other charge is transferred. Which statement describes the final charge on the rod?
Positive, because the rod has lost 400 electrons overall.
Positive, because the rod has lost 800 electrons overall.
Negative, because the rod has gained 800 electrons overall.
Negative, because the rod has gained 400 electrons overall.
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.