Red Seal Electrician Practice
AC generationQuestion 165 of 1506

An AC supply has an effective value of 120 V. What is its peak value?

  1. 84.8 V
  2. 339.4 V
  3. 76.7 V
  4. 169.7 V
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Correct answer: 169.7 V

The RMS value is 0.707 × peak, so peak = 120 ÷ 0.707 = 169.7 V. The 84.8 V choice multiplies by 0.707 instead.

Source: Trigonometry and Single Phase AC Generation for Electricians (Flinn), 3.4: AC Waveform Analysis

Practice ac generation

Questions last reviewed: 18 October 2026