The following statements for series and parallel circuits are a consequence of Kirchhoff's first and second law
In a series circuit:
The current is the same at any point
The potential difference is split across all components depending on their resistance
In a parallel circuit:
The total current is equal to the sum of the currents in each parallel branch of the circuit
The potential difference across each loop is the same
Series and Parallel Circuit Rules
The table below summarises the rules for calculating current, potential difference (i.e. voltage) and resistance within series and parallel circuits
Advantages of Parallel Circuits
Parallel circuits are incredibly useful for home wiring systems
A single power source supplies all lights and appliances with the same potential difference
If one light breaks, current can still flow through the rest of the lights and appliances
Series and Parallel Cells
Cells can also be connected in series or parallel
If the cells are connected in series, the total potential difference between the ends of the chain of cells is the sum of the potential difference across each cell
If the cells are connected in parallel, the total potential difference across the arrangement is the same as for one cell