Plugs and wires

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

  From the national grid
• What do we call the electricity supplied from the national grid?

  Main supply
• What is the voltage of the main supply in the UK?

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

  50 hertz
• What type of cable is usually used to connect appliances to the main supply?

  A three core cable
• What are the three wires inside a three core cable?

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

  Copper
• Why are the wires coated in insulating plastic?

  For safety
• What color is the live wire?

  Brown
• What does the live wire provide?

  Alternating potential difference of 230 volts
• What color is the neutral wire?

  Blue
• What is the function of the neutral wire?

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

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

  To stop the 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?

  It 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?

  A large current flows through them
• Why is it dangerous to touch plug sockets?

  Live wire still has potential difference
• What are the functions of the three wires in a plug?

  • Live wire: Provides 230 volts
  • Neutral wire: Completes the circuit
  • Earth wire: Prevents casing from becoming live
• What are the potential differences of the wires in a plug?

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