Series and parallel

Science

Definition

Series and parallel describe two basic ways to connect components in an electrical circuit. In a series circuit, components are connected end-to-end so the same current flows through each. In a parallel circuit, components are connected across the same two points so each has the same voltage.

Examples

  • Old-style Christmas lights wired in series (one burns out, all go dark)
  • Household outlets wired in parallel so each appliance gets 120V independently
  • Combining batteries in series to increase total voltage
Key Fact

Series: Rtotal = R₁+R₂+...; Parallel: 1/Rtotal = 1/R₁+1/R₂+...

Study This Concept

Practice series and parallel with free review games in these units: