A physics student rubs two identical acrylic rods with the same piece of silk cloth. One rod is then balanced horizontally on a low-friction insulating pivot so that it is free to rotate in a horizontal plane.
Explain how the student can use the second rod to show that both rods have acquired the same type of electric charge.
47 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.