An instructor wants to demonstrate how electrostatic charges can be produced by friction.
She holds a rod directly in her bare hand and rubs it with a woolen cloth. Four rods made of different materials are available:
Which two rods would both be suitable to successfully demonstrate the production and retention of electrostatic charge when held and rubbed in this way?
an aluminum rod and a brass rod
an ebonite rod and a polythene rod
a brass rod and a polythene rod
a polythene rod and an aluminum rod
452 exam-style questions on CIE IGCSE Physics 4.2 Electrical quantities, covering 4.2.1a Positive and negative charge, 4.2.1b Charging by friction and detecting charge, 4.2.1c Electrical conductors and insulators, 4.2.1d Electric fields and electric field patterns, 4.2.2a Electric current, charge and measuring current, 4.2.2b Conduction in metals and the direction of current, 4.2.2c Direct current and alternating current, 4.2.3a Electromotive force, 4.2.3b Potential difference and voltmeters, 4.2.4a Resistance, 4.2.4b Resistance of a metallic wire, 4.2.4c Current–voltage graphs, and 4.2.5 Electrical energy and electrical power. Each one has a worked solution and a mark scheme showing where the marks go.