AC generationQuestion 521 of 1506

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

  1. 30 Hz
  2. 60 Hz
  3. 1800 Hz
  4. 15 Hz
Show answer

Correct answer: 30 Hz

1800 RPM / 60 = 30 rotations per second. With two poles that is 30 cycles per second.

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

Practice ac generation

Questions last reviewed: 18 October 2026