Resistors in Series and Parallel

• Total resistance of resistors in series

  Resistors in series add together
• Calculating current in a circuit with resistors in series

  1. Calculate total resistance

  2. Divide potential difference by total resistance
• Current has to pass through each resistor in series, cannot bypass any resistor
• Equivalent resistance


  Resistors in series can be replaced by one resistor with the combined resistance
• Calculating potential difference across resistors in series

  1. Calculate total resistance

  2. Multiply resistance by current
• Total resistance of resistors in parallel


  Less than the resistance of the smallest individual resistor
• With resistors in parallel, there are two pathways for the current to take, so more total current will flow