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ASVAB · Circuits and Ohm's Law

In a series circuit with three resistors, how is the total resistance found?

Reviewed by Jordan Morley, Editorial Lead at 247SimpleTests. Written by the 247SimpleTests Editorial Team from the official source material cited on every question.

Correct answer

Add the resistances together

  1. A Divide the resistances
  2. B Multiply the resistances
  3. C Use only the largest resistance
  4. D Add the resistances together

Why this is the answer

In a series circuit, the components are connected end to end in a single path, so the total resistance is simply the sum of the individual resistances: R_total = R1 + R2 + R3. The same current flows through every component in series, while the voltage divides among them. This contrasts with a parallel circuit, where total resistance is found with a reciprocal formula and is always less than the smallest individual resistor. Recognizing series (add resistances, one path) versus parallel (multiple paths, lower total resistance) is essential circuit knowledge.
Source: ASVAB Electronics Information — Series Circuits

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About this topic: Circuits and Ohm's Law

Circuits and Ohm's Law questions ask you to calculate voltage, current, resistance or power, and to understand series versus parallel circuits — how resistance adds in series and reduces in parallel, and what happens when one component fails. This is one of 17 Electronics Information questions on circuits and ohm's law, each with a full explanation on a single study page.

New to this exam? Our ASVAB exam guide explains the format, scoring, and how to prepare.

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