An 11000 V, 3 phase, Y connected synchronous turbo alternator has 6 Ω reactance and a negligible resistance pe?

An 11000 V, 3 phase, Y connected synchronous turbo alternator has 6 Ω reactance and a negligible resistance per phase. When the field current is 8A. The open circuit voltage is 12,000 Volts. Determine the armature current when alternator developed maximum power. thank you!