A$4$pole$,50$Hz$,1500$V$,$class B $$induction machine is $$rated at$32$kW$.$It $$has a full load

speed of$1460$rpm $$and stator resistance of$2\mathrm{.}8$phase$.$

$($i$)$If $$the rotor resistance is $$increased$,$ describe with brief explanation

what happens to $$:

the value of $$maximum torque,

the slip, and

the startup torque if $$the rotor resistance is $$increased$.$

$($ii$)$Calculate the full load torque for the machine.

$($iii$)$Using standard notation for blocked rotor tests, calculate the value of$$xBR$,$

if $$the results of $$a blocked rotor test are given as:

f$=12\mathrm{.}5$Hz$,$VLL$=415$V$,$IL$=18$A$,$Input Power $=8700$W$.$

Calculate the value of$$xBR$.$