A negatively charged aluminium can is free to roll on a dry insulating surface. A charged rubber strip is brought near the can without touching it, and the can rolls away from the strip. The strip is removed and the can is connected to Earth until it is neutral. The Earth connection is then removed. What happens when the same strip is brought near the can again?
The strip is negative and the can rolls towards the strip.
The strip is positive and the can rolls towards the strip.
The strip is negative and the can remains in the same position.
The strip is positive and the can remains in the same position.
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.