Question

The given variable losses are 5kW fr a 500 KVA, 11 kV, 3-phase star connected alternator having armature resistance of 4 ohms. Calculate the full load armature current per phase.

(a) 26.24 A

(b) 20.41 A

(c) 79 A

(d) 40 A

This question was posed to me in an international level competition.

Question is from Efficiency of Synchronous Machines topic in section Efficiency and Regulation of Electrical Machines

Answer 1

Right answer is (a) 26.24 A

Easiest explanation: I = P/1.73*V = 5000/1.73*11000 = 26.24 A.