Red Seal Electrician Practice
Power factor and three-phaseQuestion 214 of 1506

A motor on a 240 V supply draws 20 A at a power factor of 0.75 lagging. A capacitor raises the power factor to 1.0. What is the line current then?

  1. 20 A
  2. 15 A
  3. 26.7 A
  4. 12 A
Show answer

Correct answer: 15 A

True power is 240 x 20 x 0.75 = 3,600 W and it does not change. At unity, I = 3,600 / 240 = 15 A.

Source: Lessons in Electric Circuits II: AC (Kuphaldt), 11.4: Practical Power Factor Correction

Practice power factor and three-phase

Questions last reviewed: 18 October 2026