Red Seal Electrician Practice
AC generationQuestion 164 of 1506

An AC voltage has a peak of 100 V. What is its instantaneous value at 225°?

  1. +70.7 V
  2. −100 V
  3. −70.7 V
  4. −50 V
Show answer

Correct answer: −70.7 V

sin 225° = −0.707, so the value is −70.7 V, in the negative half of the cycle.

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

Practice ac generation

Questions last reviewed: 18 October 2026