Here auto transformer change voltage from 600 V to 200 V. Voltage ratio (a) = 600/200 = 3 kVA rating of the auto-transformer = (a/(a - 1))*(kVA rating of auto transformer) = (3/2)*20 = 30 kVA
Voltage equation for Dc shunt generator, Eb = V + Ia*Ra V = Ish*Rsh Ish = 200/100 = 2 A Eb = V + Ia*Ra 20 = Ia*Ra Ia = 20/0.2 = 100 A I = 100 - 2 = 98 A
EXAMIANS