Some electrical equipment is housed inside a metal enclosure which is mounted on a thick rubber mat (an insulator). The equipment is connected to a 240 V mains supply, but the earth wire has become disconnected inside the plug. A fault develops and the live wire comes loose, touching the interior of the metal enclosure.
Which statement correctly describes this situation?
A large fault current flows immediately through the rubber mat, causing the fuse to blow.
The metal enclosure is maintained safely at 0 V0\text{ V}0 V because of the rubber mat.
A continuous electric current flows through the metal enclosure to the surrounding air.
The metal enclosure becomes live (240 V240\text{ V}240 V), and someone touching it will receive a dangerous electric shock.
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.