Mains Electricty

• What type of current is mains electricity in the UK?

  Alternating current (AC)
• What is the frequency of alternating current in the UK?

  50 hertz
• What is the potential difference of mains electricity in the UK?

  230 volts
• How are electrical appliances connected to mains electricity?

  Using three core cable
• What are the three wires in a three core cable?

  Live wire, neutral wire, Earth wire
• What is the function of the live wire?

  It carries a potential difference from the supply
• What is the potential difference of the live wire?

  230 volts
• What is the function of the neutral wire?

  It completes the circuit with the live wire
• What is the potential difference of the neutral wire?

  0 volts
• What is the function of the Earth wire?

  It is a safety wire
• Why is the live wire considered dangerous?

  It can be fatal if touched
• What happens if someone touches the live wire?

  A current flows through them into the Earth
• Why can appliances with metal cases be dangerous?

  If the live wire touches the case
• How does the Earth wire prevent electric shocks?

  It directs current to the ground
• What happens when the metal case becomes live?

  A huge current flows to the Earth
• What is the role of the fuse in the circuit?

  It melts and shuts off the current
• What are the functions of the live wire, neutral wire, and Earth wire?

  • Live Wire: Carries potential difference from supply (230 volts)
  • Neutral Wire: Completes circuit with live wire (0 volts)
  • Earth Wire: Safety wire directing current to the ground
• What are the dangers associated with the live wire and metal cases of appliances?

  • Live wire can be fatal if touched
  • Metal cases can become live if the live wire touches them
  • Earth wire prevents electric shocks by directing current to the ground