A kettle with a metal case is connected to the mains supply by a cable containing three wires.
The Table shows information about the three wires.
Table
| Wire | Colour of insulation |
|---|---|
| live | brown |
| neutral | blue |
| earth | green and yellow stripes |
What is the potential difference between the live wire and earth?
Choose your answer from the list.
0 V 12 V 50 V 230 V
What is the potential difference between the neutral wire and earth?
Choose your answer from the list.
0 V 12 V 50 V 230 V
Which wire is a safety wire that only carries a current if there is a fault?
A fault in the kettle makes the live wire touch the metal case.
Explain how the earth wire protects a person who then touches the metal case.
16 exam-style questions on OCR GCSE Physics 8.2 Powering Earth, covering 8.2.1 Renewable and non-renewable energy resources, 8.2.2 Patterns and trends in energy use, 8.2.3 The national grid, 8.2.4 Step-up and step-down transformers, 8.2.5 Efficiency of the national grid, 8.2.6 Transformers and power transmission at high voltage, 8.2.7 The UK domestic supply, 8.2.8 Direct and alternating potential difference, 8.2.9 Live, neutral and earth wires, and 8.2.10 Dangers of mains electricity. Each one has a worked solution and a mark scheme showing where the marks go.