Red Seal Electrician Practice
Power factor and three-phaseQuestion 213 of 1506

Two 120 V sources are 120 degrees apart. Each feeds its own 10 kW resistive load (83.33 A), and the two loads share one return wire. What current flows in that return wire?

  1. 83.33 A
  2. 0 A
  3. 166.7 A
  4. 41.7 A
Show answer

Correct answer: 83.33 A

The two currents are 120 degrees apart, so they do not cancel in the shared wire. Their sum is the same 83.33 A as in each hot wire.

Source: Lessons in Electric Circuits II: AC (Kuphaldt), 7.2: Three-phase Power Systems

Practice power factor and three-phase

Questions last reviewed: 18 October 2026