Topic 4 - Electricity

• Different components of a LAN?

  cell, switch, ammeter, voltmeter, bulb, resistor
• Current units = amps ( A )
• Voltage units = Volts ( V )
• Electricity is the flow of charges
• For a current to flow in a circuit you need?

  Closed loop, a cell or power supply
• High resistance = hard for electricity to flow = small current
• Low resistance = easy for electricity to flow = large current
• Thick wire = Low resistance
• Series circuit: if one bulb breaks they all do, current is the same everywhere, more bulbs will be dimmer ( resistance is higher )
• Parallel circuit = if one bulb breaks the other bulbs will still work, if you add more bulbs they stay bright
• Dangers of electricity: fires, burns, powerful shocks
• Fuses = used in plugs to protect the circuit from overheating.
• Circuit breakers = a device that automatically cuts off the current in a circuit when it reaches a certain level
• What is a brown wire which is part of a circuit called?( in a cable )

  Live wire
• What is a blue wire which is part of a circuit called?( in a cable )


  Neutral wire
• What is the green and yellow wire called?( works with fuse)


  Earth wire