A series circuit is formed when the circuit elements are connected together on a single conducting path. If you can trace a path from the positive terminal of the voltage source around the circuit to the negative terminal of the voltage source without lifting your pencil from the paper, the circuit is a series circuit. A break in any part of the single conducting path will stop the current flow in the circuit.

The following video gives a more in-depth analysis of series circuits:

Visit Series Circuit, view the animation and write the rules for voltage V, current I, and resistance R in your notes.

Practice Problem:

A series circuit contains a 6 V battery, a 68 Ω resistor, and an 82 Ω resistor. Determine the current in each resistor?

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Need a hint?

Identify known variables: V = 6 V, R1 = 68 Ω, R2 = 82 Ω
Determine the equivalent resistance: R_equivalent = R₁+R₂ = 68 Ω+82 Ω=150Ω
Equation: I + V R_equivalent
Substitute variables and solve: I = 6V 150 Ω = 0.04 A

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Check Your Answer

0.04 A