AC generationQuestion 522 of 1506

A four-pole alternator turns at 1800 RPM. What is the frequency?

  1. 30 Hz
  2. 120 Hz
  3. 7200 Hz
  4. 60 Hz
Show answer

Correct answer: 60 Hz

f = P x N / 120 = 4 x 1800 / 120 = 60 Hz.

Source: Trigonometry and Single Phase AC Generation for Electricians (Flinn), 3.5: Frequency and Alternators

Practice ac generation

Questions last reviewed: 18 October 2026