A PMAC machine is connected in YY$.$ It has $1010$ poles, IF$=25$AIF$=25$A$,$ Lm$=5$mHLm$=5$mH$.$ It is supplied from a source of l$-$n voltage up to $600$V$600$V while the maximum stator current is $28$A$28$A$.$

$($a$)$ What is the maximum torque this motor can produce with the most efficient operation?

$($b$)$ Under this torque what is the maximum speed the motor can reach without field weakening?

$($c$)$ If field weakening is used with Id$10$AId$10$A$,$ what will be the maximum speed and corresponding torque?

$($d$)$ Can this motor operate at $150$Nm$150$Nm and mechanical $($rotor$)$ speed of $900$rpm$900$rpm$?$ If so$,$ what will be the stator voltage and current?