Physics

• AC


  Alternative Current
• DC


  Direct Current
• Direct Current (DC)


  • Flows in one direction
  • Produced by batteries and cells
  • Cannot be transferred efficiently over large distances
• Battery supported devices


  • Mobile phone
  • Torch
  • Tablet
• Alternating Current (AC)


  • Constantly changes direction
  • Produced by most generators and used in mains electricity
  • Can be transferred efficiently over large distances
• Mains supported devices


  • Toaster
  • Microwave
  • Lamp
• In the UK we have 230V coming out of the wall socket
• Insulation


  Material used to prevent the flow of electricity, heat or sound
• Fuses


  Small cylinder-shaped devices with a thin wire inside that melts when the current becomes too high, causing the fuse to blow and prevent damage
• Fuses


  • Thin wire inside melts when current becomes too high
  • Fuse blows up when wire melts
  • Cannot be used again after blowing, needs to be replaced
• Fuse sizes


  • 3A
  • 5A
  • 13A
• Pros of fuses


  Can prevent fires and damage to devices
• Cons of fuses


  • Slow in acting
  • Cannot protect the users
• Choosing the right fuse is important