A high torque cage induction motor has the following name plate data: RATING POLES 37 kW 4 FREQUENCY 50 Hz CONNECTION DELTA INSULATION Class E PHASES 3 VOLTAGE 415 V CURRENT 64 A SPEED 1465 rev/min The full equivalent circuits parameters are: RC = 4922 XM = 302 R₁ = 0.1892 R2' = 0.293 2 Χ1 = 0.326 Ω X2' = 0.5392 The friction and windage loss is 0.910 kW and may be considered constant over speed range 1500 rev/min to 1000 rev/min. It is required to control the speed of the motor over a limited range by voltage control. Given that mechanical load has a Speed Vs Torque characteristic, where the torque is directly proportional to the speed of the motor SQUARED. Determine for a motor speed of 1380 rev/min: 3.1.1 the required stator line voltage; 3.1.2 the motor efficiency at 1380 rev/min; [8 Marks] [2 Marks] 3.1.3 comment on the suitability of running the motor in this reduced voltage mode. [2 Marks]