Plug

• How many wires are there ?

  3

  
• Earth wire(0v) is safety wire where does it connect to?

  Outer case
• What does earth wire do?

  Protects you and stops electric shocks
• Live wire(230 volts in uk)

  It takes current into appliancr and is connected to switch and fuse
• What does cable grip do

  Presses on outer cable to hold it in place
• Neutral(0 volts) what does it do?

  Brings current out of appliance
• Most plugs contain a fuse connected to the live wire
• What happens to current flows through fuse


  Heats up
• The thin wire will melt?

  If too much current flows through fuse and breaks circuit so current can't flow
• What do circuit breakers do?

  detect changes in the current and automatically switch off the power if there's an unexpected change in the current.
• Circuit breakers

  • Faster than fuse
  • Don't need to be replaced after current is broken because switch inside resets them
• What does brown live wire carry?

  alternating potential difference from the power supply.
• How does earth wire protect us from shocks ?

  The earth wire is connected to the case and provides a route to so the current flows to the ground through the earth wire rather than through a person.
• Different devices draw different amounts of current when working correctly, so they need different fuses.

  A fuse should be chosen that's rated slightly higher than the current the device usually uses.
• Why do fuses melt

  there's a fault and a high current flows through the earth wire.
• why are fuses useful?

  prevent devices from drawing too much current and overheating.
• why are fuses connected to live wire

  they carry the current