An electrical appliance with a plastic outer case is described as being double insulated. It is connected to the mains using a cable containing only live and neutral wires, with no earth wire.
What is the reason why an earth wire is not needed for this appliance?
The plastic case prevents the internal wires of the appliance from overheating.
The plastic case completes the circuit and allows the appliance to work.
The plastic case is an insulator and cannot become live, preventing any risk of electric shock.
The plastic case ensures the appliance only draws a very small current.
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.