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ASVAB · Circuits and Ohm's Law

In a parallel circuit with three resistors of 10Ω, 20Ω, and 20Ω, which branch carries the most current?

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

The 10Ω branch — lower resistance means higher current flows through that branch (I = V/R; same voltage, lower resistance = more current)

  1. A All branches carry equal current
  2. B Parallel circuits have no current flow
  3. C The 10Ω branch — lower resistance means higher current flows through that branch (I = V/R; same voltage, lower resistance = more current)
  4. D The 20Ω branches — they are identical so they share equally

Why this is the answer

Parallel circuit current distribution: In a parallel circuit, ALL branches share the SAME VOLTAGE (equal to the supply voltage). Current in each branch is determined by Ohm's Law: I = V/R. The 10Ω branch has the lowest resistance, so with the same voltage applied, it carries the most current (twice as much as each 20Ω branch). This is why fuses and circuit breakers are connected in series — if resistance drops (short circuit), current in that branch increases dramatically, blowing the fuse.

Source: ASVAB EI, Parallel Circuits — Current Distribution

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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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