What is the primary function of an earth wire connected to a metal-cased electrical appliance?
to prevent the current from becoming too large during normal operation
to provide a safe path to the ground if a fault occurs and the live wire touches the metal casing
to ensure the appliance operates at a power level that saves electrical energy
to step down the high voltage of the mains supply to a safer value
135 exam-style questions on CIE IGCSE Physics Electrical safety, covering Electrical safety. Each one has a worked solution and a mark scheme showing where the marks go.