Red Seal Electrician Practice
TransformersQuestion 246 of 1506

A donut-shaped current transformer is slipped over a bus conductor. What does that conductor act as?

  1. A many-turn secondary winding
  2. A single-turn primary winding
  3. A core-saturating winding
  4. A grounded shield for the secondary
Show answer

Correct answer: A single-turn primary winding

The conductor passes once through the opening, so it is a primary of one turn.

Source: Lessons in Electric Circuits II: AC (Kuphaldt), 10.7: Special Transformers and Applications

Practice transformers

Questions last reviewed: 18 October 2026