A $3-$phase, $22$ Hp$,460$ V $($line$-$to$-$line rms$),60$ Hz$,1160$ rpm induction motor

has a starting current of $150$ A$.$ The ratio of the starting current and the full load supply current

$($per$-$phase$)$ is $5.$ The input power factor $($PF$)$ is $0\mathrm{.}8$ lagging at the rated condition. The rotational

losses are $1500$ W$.$

$($a$)$ Determine the number of poles of the machine.

$($b$)$ Determine the rated input power at the full load condition.

$($c$)$ Determine the efficiency.

$($d$)$ Determine the stator resistance $($per$-$phase$).$