Red Seal Electrician Practice
AC theoryQuestion 931 of 1506

An inductor has a reactance of 15 Ω at 50 Hz. What is its reactance at 150 Hz?

  1. 5 Ω
  2. 15 Ω
  3. 45 Ω
  4. 135 Ω
Show answer

Correct answer: 45 Ω

Reactance is directly proportional to frequency. Three times the frequency gives three times the reactance: 15 × 3 = 45 Ω.

Source: Lessons in Electric Circuits II: AC (Kuphaldt), 3.2: AC Inductor Circuits

Practice ac theory

Questions last reviewed: 18 October 2026