DC Network Theorems Unit 4 – Kirchhoff's Loop Equations
UNIT 4 – KIRCHHOFF'S LOOP EQUATIONS
UNIT OBJECTIVE
At the completion of this unit, you will be able to use loop equations by applying Kirchhoff's
laws to a series/parallel circuit.
UNIT FUNDAMENTALS
A loop is a closed circuit path. Shown is one example of a loop, where a single path is the only
possible loop for the series circuit.
Kirchhoff's voltage law states that the algebraic sum of voltages in a closed loop equals zero.
A series/parallel circuit, such as this one, consists of more than one loop. To generate loop
equations, use the voltages around each loop. One loop is from the - side of VS, through R1 and
RS, and back to VS. The loop equation, therefore, is VR1 + VRS = VS.