Series & Parallel Circuits (DP IB Physics: SL)

• 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