Red Seal Electrician Practice
AC theoryQuestion 990 of 1506

Why does the text suggest checking the voltage drops against the total in a long AC calculation?

  1. Kirchhoff’s laws do not hold in AC, so a check is a waste of time
  2. The check removes the need to use Ohm’s law at all
  3. A quick Kirchhoff check finds errors before the last step
  4. The check gives the phase angle of the source
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Correct answer: A quick Kirchhoff check finds errors before the last step

Many complex-number steps give many chances for error, so a cross-check saves rework.

Source: Lessons in Electric Circuits II: AC (Kuphaldt), 5.4: Series-parallel R, L, and C

Practice ac theory

Questions last reviewed: 18 October 2026