Get Wired 102 Introduction to the Basic Installation of Lighting Fixtures and Branch Circuits Practice Test

In a series circuit, the same current flows through each resistor, and the voltages across them add up. The total resistance is found from V_total = I × R_total, while V_total = V1 + V2 = I × R1 + I × R2. Since the current I is the same through both resistors, R_total = R1 + R2. So the total resistance is the sum of the two resistors. It isn’t the product, difference, or ratio because those relationships don’t reflect how voltage adds and current stays constant in series.