fundamentals of circuits

• what is a circuit?


  A closed loop with a power source e.g a cell
• what is current?


  • measure in amps or amperes
  • measure of flow of electrons around a circuit
• what is potential difference 


  • force driving the flow of electrons - provided by the cell/battery
  • also known as voltage
  • measured in volts
• what is resistance


  everything that resists or opposes the flow of electrons

  measured in ohms
• what happens to the current in series?


  • it is never used up
• what happens to the current, when there is a high potential difference?


  • the current is also high
• when energy is transferred to the light, what is it converted to?

  • thermal energy
  • light energy
• what happens to the current in parallel?


  • the current in branches adds up to the total current leaving the cell
• what happens to the potential difference in a parallel circuit 


  the potential difference across each brand of the circuit is the same