Plugs

• Humans have a potential difference of zero volts, so touching the live wire can cause a large current to flow through them, resulting in an electric shock
• Live wire has a potential difference of 230 volts


  Causes electricity to pass through neutral or earth wire, leading to electric shock if touched
• Earth wire


  Color: Striped green and yellow, Doesn't normally carry a current, Potential difference of zero volts, Prevents appliance casing from becoming live
• Components of a three-core cable

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

  Color: Blue, Completes the circuit by carrying away current, Potential difference of zero volts
• Earth wire provides an alternative pathway for current to flow away


  Prevents dangerous electricity from passing through humans
• Live wire


  Color: Brown, Provides alternating potential difference of around 230 volts from the main supply
• Electricity passes through the neutral wire


  Neutral wire has a potential difference of zero volts, causing electricity to flow out of the device
• It's important to never touch plug sockets even if they're switched off, as the live wire still has a potential difference
• The large majority of electricity in the UK comes from the national grid which distributes power across the country to homes
• The electricity supplied by the national grid is an alternating current of 230 volts and operates at 50 hertz