A 3-φ induction motor having a star-connected rotor has an induced e. m.f. of 80 volts between slip-rings at standstill on open-circuit. The rotor has a resistance and reactance per phase of 1 Ω and 4 Ω respectively. Calculate current/phase and power factor when slip ring is connected to star-connected rheostat of 3Ω per phase.