Red Seal Electrician Practice
TransformersQuestion 1070 of 1506

What is the magnetizing current in a transformer?

  1. The current that sets up the core flux
  2. The load current that flows in the secondary winding
  3. The current that flows only in the iron of the core
  4. The short-circuit current of the secondary winding
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Correct answer: The current that sets up the core flux

It supplies the mmf needed for the flux. In an ideal case it lags the voltage by 90 degrees.

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

Practice transformers

Questions last reviewed: 18 October 2026