Series and parallel circuits

• Series


  Same loop
• Parallel


  Adjacent loop
• How the potential difference across two components varies when connected in series and parallel

  1. Series: Total P.D is shared between each component

  2. Parallel: P.D across each component is the same
• Total resistance of two resistors connected in parallel

  Less than the smallest of the two individual resistances
• Total resistance of two resistors connected in series

  Equal to the sum of the two individual resistances
• Current in a series circuit

  • The same at all positions since the charge only has one path to flow through
• Current in a parallel circuit

  • Shared between the different branches, when the charge reaches a junction it splits
• How to connect an ammeter in a circuit to measure current

  Ammeters should be connected in series with the component that they are measuring current through
• How to connect a voltmeter in a circuit to measure potential difference

  Voltmeters should be connected in parallel to the component that they are measuring the potential difference of
• Connecting lamps in parallel

  If one lamp blows, the rest will be unaffected and can still receive current (i.e. the circuit is still complete)