Resistors

Resistors in Series

The figure below shows two resistors connected in series between points A and B.

Two resistors in series.

When resistors are connected in series, total resistance (R_t) is equal to the sum of the individual resistances.

As an equation:

Note: The subscript n denotes any number of additional resistances that might be in the equation.

Example:

In the figure below a series circuit consisting of three resistors: one of 10 Ω, one of 15 Ω, and one of 30 Ω, is shown. What is the total resistance?

Series circuit with three resistors.

Solution: