Question

Two single phase transformers A and B are operating in parallel having different impedance and identical x/r ratio. Impedance of A is Za and impedance of B is Zb, both sharing a load of Sl. Then the load shared by transformer B is?

(a) Sl*(Zb/(Za+Zb))

(b) Sl*(Za/(Za+Zb))

(c) Sl*(Zb*Za/(Za+Zb))

(d) Sl*(Zb+Za/Zb))

The question was asked during an interview.

I'm obligated to ask this question of Parallel Operation of Single Phase Transformers topic in chapter Transformers of Electrical Machines

Answer 1

The correct answer is (b) Sl*(Za/(Za+Zb))

The best explanation: The load sharing is based on the inverse of the  kVA rating.