Red Seal Electrician Practice
TransformersQuestion 1095 of 1506

A bench technician needs isolation from the power line but the same voltage level. Which device fits?

  1. A step-up transformer
  2. A saturable reactor
  3. A variable autotransformer
  4. An isolation transformer with a 1:1 ratio
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Correct answer: An isolation transformer with a 1:1 ratio

An isolation transformer gives isolation without changing the voltage or current.

Source: Lessons in Electric Circuits II: AC (Kuphaldt), 10.3: Electrical Isolation

Practice transformers

Questions last reviewed: 18 October 2026