Series and Parallel Circuits

• In a series circuit the potential differences of cells add up to give the total potential difference of the battery
• In series circuits the total potential difference of the battery is shared between the various components

  $V_{total}=$$V_1+$$V_2+$$...$
• In series circuits the current is the same throughout the circuit

  $I_1=$$I_2=$$...$
• In series circuits the resistance add up to create the total resistance

  $R_{total}=$$R_1+$$R_2+$$...$
• If one component in a series circuit breaks all other components will break too
• If one component in a parallel circuit breaks the others are not affected
• In parallel circuits the potential difference is the same across all components $V_1=$$V_2=$$...$
• In parallel circuits current is shared between branches

  $I_{total}=$$I_1+$$I_2+$$...$
• Two resistors in parallel will have a total resistance that is lower than the smallest resistor ; this is because the current has more than one path to choose so the total current increases and therefore the resistance decreases