A positively charged metal weighing pan is supported on dry glass legs. Nearby are an earthed metal rail and an isolated metal cabinet. A technician stands on a thick rubber mat and has bare hands, a dry rubber glove and a dry plastic ruler.
Which action allows electrons to flow from Earth onto the weighing pan?
The technician touches the pan with one bare hand and the isolated metal cabinet with the other.
The technician touches the pan with one bare hand and the earthed metal rail with the other.
The technician holds the dry plastic ruler so that it touches both the pan and the earthed metal rail.
The technician grips the pan through the dry rubber glove while touching the earthed metal rail.
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.