Red Seal Electrician Practice
TransformersQuestion 1101 of 1506

An ideal transformer feeds a resistive load. How are the primary and secondary currents related in phase?

  1. They are in phase, with no phase shift.
  2. They are 90 degrees apart, with the secondary leading.
  3. They are 180 degrees apart, with the secondary reversed.
  4. They are 120 degrees apart, as in a three-phase supply.
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Correct answer: They are in phase, with no phase shift.

Ideally, a transformer gives zero phase shift for both voltage and current between the windings.

Source: Lessons in Electric Circuits II: AC (Kuphaldt), 10.4: Phasing

Practice transformers

Questions last reviewed: 18 October 2026