Red Seal Electrician Practice
AC theoryQuestion 968 of 1506

How do impedances combine in a series AC circuit?

  1. They add, using complex (vector) addition
  2. They add as plain numbers, ignoring the phase angles
  3. They combine using the reciprocal formula
  4. Only the largest impedance counts in the total
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Correct answer: They add, using complex (vector) addition

Series impedances add like series resistances, but the addition must keep the phase angles.

Source: Lessons in Electric Circuits II: AC (Kuphaldt), 4.3: Series Resistor-Capacitor Circuits

Practice ac theory

Questions last reviewed: 18 October 2026