electricity

• Components


  • Selectric power: call/barjory
  • Controul
  • S 1
  • +low - switch
  • Filament lamp
  • LJ fuse Coreak if too much corrent)
  • Diode
  • LED: emit light when curnant Hlows through
  • Ammeter: measure current
  • Voltmeter: measure PD
  • Resistors: Fixed-
  • Resistors: variable: modity amount of resistance
  • LDR: resistance dependant on light intensity (high in dark, low in light)
  • Thermistor: resistance falls out high temps, low temps
• Charge flow


  1. Charge takes flowy evenent

  2. Period of se charge = (columes) (c)
• Series circuit


  Single loop
• Parallel circuit


  More than 1 loop
• Series circuit


  If one component disconnects the whole thing breaks
• Parallel circuit


  PD is shared across all components
• Parallel circuit


  If one component breaks, the overall circuit will be in tact
• PD


  Potential difference
• AC


  Alternating current: direction is in all directions
• DC


  Direct current: charge flows is same direction
• UK main when we use alternating voltage, it fluctuates between +/- 240V, 50HZ
• DC


  Produced by divided voltage
• Plugs & wires


  • Live wire: Brown - Alternating potential difference. Around 230V from the main supply
  • Neutral wire: Blue - Completes circuit by carrying away current
  • Earth wire: Green/yellow - Provides alternative path for current to flow away
• Live wire has PD


  Touching it would give an electric shock
• Earth wire provides alternative path for current to flow away, preventing dangerous activity
• Electricity flows through live wire & earth


  Due to the PD between them
• Fuses break when current gets too high, preventing damage and electric shock
• Fuses come in different ratings to match the current of the circuit
• Circuit breaker


  Breaks when surge, can be reset
• Surge on live wire

  Causes damage and electric shock
• Earth wire provides alternative path for current to flow away during a surge
• Double insulation


  No exposure to metal parts, plastic doesn't conduct electricity, doesn't need earth wire