A 3.3 kV, 20-pole, 50 Hz, 3-phase, starconnected induction motor has a slip-ring rotor of resistance 0.025 W and standstill reactance of 0.28 W per phase. The motor has a speed of 294 rpm when full-load torque is applied. Compute
(a) slip at maximum torque, and
(b) the ratio of maximum to full-load torque. Neglect stator impedance.