Which of the following is the main advantage of an auto-transformer over a two winding transformer – Transformer MCQ#76

Which of the following is the main advantage of an auto-transformer over a two winding transformer:

1. Elimination of Eddy current losses
2. Copper losses are negligible
3. Saving in winding material
4. Reduced Hysteresis losses

Correct answer: 3. Saving in winding material