Plugs and Wires

• Where does the majority of electricity in the UK come from?

  From the national grid
• What is the main supply voltage in the UK?

  230 volts
• What is the frequency of the alternating current in the UK?

  50 hertz
• What does plugging an appliance into a socket connect it to?

  The main supply
• How many wires are in a three core cable?

  Three wires
• What are the names of the three wires in a three core cable?

  Live wire, neutral wire, earth wire
• What material are the wires 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?

  The casing could become live
• How does the earth wire prevent electric shocks?

  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 is the potential difference of the neutral wire?

  Zero volts
• 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 has a potential difference
• What are the functions of the three wires in a plug?

  • Live wire: Provides alternating potential difference
  • Neutral wire: Completes the circuit by carrying away current
  • Earth wire: Stops appliance casing from becoming live
• What are the safety measures associated with the earth wire?

  • Provides an alternative pathway for current
  • Prevents electric shocks from faulty appliances
  • Ensures appliance casing remains safe to touch
• What are the potential differences of the wires?

  • Live wire: 230 volts
  • Neutral wire: 0 volts
  • Earth wire: 0 volts