What is the primary function of an earth wire in a domestic electrical appliance with a metal case?
to prevent the current in the circuit from exceeding a safe level
to safely direct current to the ground if a fault causes the live wire to touch the metal case
to provide a return path for current to the power source during normal operation
to reduce the total electrical energy consumed by the appliance
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.