Plugs+Wires

• In the UK, the large majority of our electricity comes from the national grid which distributes power across the country to our homes
• Main supply


  Alternating current of 230 volts at 50 hertz
• Three core cable

  • Live wire
  • Neutral wire
  • Earth wire
• Live wire


  Provides the alternating potential difference of around 230 volts from the main supply
• Neutral wire


  Carries away current to complete the circuit, has a potential difference of zero volts
• Earth wire


  Doesn't normally carry a current, has a potential difference of zero volts, provides an alternative pathway to stop the appliance casing from becoming live
• Live wire at 230 volts


  Electricity passes through neutral wire or earth wire due to difference in voltage
• Humans have a potential difference of zero volts, so if we touch the live wire it will cause a large current to flow through us in the form of an electric shock
• It's important to never touch plug sockets even if they're switched off, as the live wire still has a potential difference and any contact could result in a shock