Question

Below is the circuit diagram for delta-delta transformer have a transformation ratio ‘k’. The current flowing in the windings of phase r-y in the below diagrams is?

(a) k*I/1.73

(b) I/k*1.73

(c) 1.73*k*I

(d) 3*k*I

I got this question during an internship interview.

This intriguing question comes from Three Phase Transformers topic in portion Transformers of Electrical Machines

Answer 1

The correct answer is (a) k*I/1.73

To elaborate: The phase current will be reduced by 1/1.73.