Series and parallel circuits: Electricity: Physics: GCSE (9:1)

• Series circuit


  A circuit where electrical components are connected one after another in a single loop (a circuit that only has one path for the current to flow through)

  
• What happens when one component breaks in a series circuit?

  The current will not be able to flow round the circuit; if one component breaks, then all of the other components stop working
• Rule for current in series


  The same current passes through each component connected in series

  
• Rule for potential difference in series

  The total potential difference of the power supply is shared between components connected in series

  
• Rule for resistance in series

  The total resistance of two components connected in series is the sum of the resistance of each component

  
• Parallel circuit


  A circuit where electrical components are connected alongside each other on multiple loops; a circuit that has multiple paths for the current to flow through

  
• What happens if one component breaks in a parallel circuit?

  The current can still flow round the circuit through one of the other paths; if one component breaks, the other components still work
• Rule for current in parallel

  The total current through the whole circuit is the sum of the currents through the separate components

  
• Rule for potential difference in parallel

  The potential difference across each component is the same

  
• Rule for resistance in parallel

  The total resistance of two resistors is less than the resistance of the smallest individual resistor

  
• I(1) = I(2) = I(3)


  The mathematical relationship for the current through components connected in series

  
• V(total) = V(1) + V(2)


  The mathematical relationship for the total potential difference in a circuit when components are connected in series

  
• R(total) = R(1) + R(2)


  The mathematical relationship for the total resistance in a circuit when components are connected in series

  
• I(total) = I(1) + I(2)


  The mathematical relationship for the total current in a circuit when components are connected in parallel

  
• V(1) = V(2) = V(3)


  The mathematical relationship for the potential difference across components connected in parallel