Red Seal Electrician Practice
TransformersQuestion 1076 of 1506

How do the load current in the secondary and the induced primary current compare in phase?

  1. They are 180 degrees apart
  2. They are in phase with each other
  3. They are 90 degrees apart
  4. They are 45 degrees apart
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Correct answer: They are 180 degrees apart

The primary current produces a counter mmf that cancels the secondary mmf, so no extra flux is made.

Source: Lessons in Electric Circuits II: AC (Kuphaldt), 10.1: Mutual Inductance and Basic Operation

Practice transformers

Questions last reviewed: 18 October 2026