A 3 phase ,60 Hz,220 V,5 Hp,6 pole, delta connected wound rotor induction motor has the following per phase parameters referred to the stator : r1=0.545 Ω & r2=0.541 Ω & Xeq=1.68 Ω The full load slip is 5% .The line current during starting is not to exceed 3 times the normal current. The load torque is given by: Tload(s) = 40.65 + 24.78 (1-s)2 N.m. Neglecting the no load current ,investigate the effect of using the following starting methods on motor current, supply current and starting torque. a) Star/delta switch b) Auto transformer starting c) Adding a resistance to the rotor circuit