Calculating Resistance in Series and Parallel Circuits Basic Formulas for Rapid Computation of Circuit Resistance

Introduction Informational lecture by Fred Baker Electronics Instructor for U.S. Navy

Topics of Discussion Resistance totaling values, dependent on the circuit structure Knowing how to calculate resistance depending on circuit structure Understanding these basics can save valuable time and effort

Resistance Rules for Series Circuits Series circuits are always one-for-one additive Rt = R1 + R2 + R3 + Rn

Series Circuit Sample of a Series Circuit layout R1 R2 R3

Solving for Series Resistance Calculate the resistance using the series formula: Rt = R1 + R2 + R3 + Rn Rt = 20W + 30W + 50W = 100W R1=20W R2=30W R3=50W

Resistance Rules for Parallel Resistance Circuit Parallel circuits are reciprocally additive Rt = 1 1 + 1 + 1 R1 R2 R3

Parallel Circuit Sample of a Parallel Circuit layout R1=20W R2=30W

Solving for Parallel Resistance Calculate using reciprocal formula: Rt = 1 / 1/R1 + 1/R2 + 1/Rn Rt = 1/1/20W + 1/30W + 1/50W Rt = 1/0.05W + 0.033W + 0.02W Rt = 1/103W = 9.70W R1=20W R2=30W R3=50W

Summary Determine the type of circuit layout you are working with Apply the correct formula Verify answer by double-checking math