T2: electricity

• insulator = material that doesnt conduct electricity - eg. plastic
• double insulation is the case of appliance is plastic = no need for earth wire
• earthing = if case is metal - earth wire attached in case live wire touches case and electrifies it
• circuit breaker = electromagnetic switch that is sensitive to current change
• fuse = thin piece of wire that's connected to live wire and break is current too high
• AC?

  AC = alternating current

  electrons move back and forth
• DC?

  DC = direct current

  electrons move in one direction - eg. in batteries
• parallel circuits:

  • more than one loop
  • each branch has: same voltage - less resistive path = higher current
  • parallel better for lights = if one breaks rest still works
• series circuit:

  • only has one loop
  • voltage = splits between components - more resistance = more voltage
  • current = stays the same
• LDR?

  light dependant resistor
• LDRs change resistance by light intensity

  • lots of light = low resistance
  • less light = high resistance
• thermistors?

  temperature dependant resistors
• thermistors change resistance because of temperature

  • high temp = low resistance
  • low temp = high resistance
• resistance: the tendency of a material to oppose the flow of electricity through it
• resistance - high:

  • current = smaller - slows
  • voltage = higher - more energy
• current = the rate of flow of charge
• current is measured in amps (A)
• voltage = the energy amount per electron
• voltage is measured in volts (V)