(Solved): A 3 phase Y connected synchronous generator is rated at 120MVA,13.2kV,0.85 P.F lagging and 60Hz. ...

A 3 phase Y connected synchronous generator is rated at $120\mathrm{MVA},13.2\mathrm{kV},0.85$ P.F lagging and $60\mathrm{Hz}$. Its synchronous reactance is $0.7?$ and armature resistance is negligible: a. What is the per phase internal generated voltage ${\mathrm{E}}_{\mathrm{A}}$ and torque angle under rated conditions? b. What is its voltage regulation at rated conditions? c. If the friction and windage losses are $10\mathrm{MW}$, what is the efficiency of the generator? d. If the generator is now connected to a 120 MVA 0.5 PF lagging load, how much $\%$ increase in field current is required to keep the terminal voltage at $1\mathrm{pu}$. e. Draw the phasor diagram of the before and after change in power factor.