Plugs and Wires

• What is the main source of electricity in the UK?

  The national grid
• What is the frequency of the electricity supply in the UK?

  50 hertz
• What is the voltage of the main supply in the UK?

  230 volts
• What type of current is supplied by the national grid?

  Alternating current
• What does a three core cable contain?

  Live wire, neutral wire, earth wire
• What material are the wires in plugs and cables made of?

  Copper
• Why are the wires coated in insulating plastic?

  For safety
• What color is the live wire?

  Brown
• What is the function of the live wire?

  Provides alternating potential difference
• What color is the neutral wire?

  Blue
• What does the neutral wire do?

  Completes the circuit by carrying away current
• What color is the earth wire?

  Striped green and yellow
• What is the role of the earth wire?

  Stops appliance casing from becoming live
• Why does the earth wire not normally carry a current?

  It has a potential difference of zero volts
• What happens if the live wire touches the appliance casing?

  It could cause an electric shock
• How does the earth wire prevent electric shock?

  Provides an alternative pathway for current
• Why does electricity flow from the live wire to the neutral wire?

  Due to the difference in voltage
• What happens if a person touches the live wire?

  It causes a large current to flow through them
• Why is it dangerous to touch plug sockets?

  Live wire still has a potential difference
• What are the key components of a three core cable?

  • Live wire (brown)
  • Neutral wire (blue)
  • Earth wire (striped green and yellow)
• What are the potential dangers of touching the live wire?

  • Electric shock
  • Large current flow through the body
  • Risk of serious injury or death
• What is the significance of the potential difference in electrical safety?

  • Live wire: 230 volts
  • Neutral and earth wires: 0 volts
  • Difference causes current flow