A 400-V, 50-Hz, 2500 KVA, Y-connected synchronous generator with a rated field current of 6 A was tested, and the following data were taken:
(i) Open circuit voltage was measured to be 440 V.
(ii) Short circuit current was found to be 200 A.
(iii) When a dc voltage of 13 V was applied to two of the terminals, a current of 30 A was measured.
Find the value of the armature resistance.