Series and Parallel Circuits

Components in a series circuit are in a loop like a daisy chain. Components in a parallel circuit are stacked up like the rungs of a ladder.

In a series circuit, the voltages (p.d. or potential difference) across each component add up to the same voltage as the battery or power supply. The current is the same everywhere.

In a parallel circuit, the currents through each component add up to equal the current leaving the battery or power supply. The voltage is the same everywhere.

When cells or batteries are connected in series, their voltages add up, provided that they are all facing the same way.