spinning industry, a 205 V, 6 pole shunt motor runs at a speed of 1250 rpm gives an output of 7 HP with an armature current of 38 A. The armature winding is wave connected and it has 690 conductors. Its armature resistance is 0.3 and drop at each brush is 1 V. Find (i) Useful torque, (ii) Total torque, (iii) Useful flux per pole and (iv) Rotational losses occurring in the motor. [

In a spinning industry, a 205 V, 6 pole shunt motor runs at a speed of 1250 rpm gives an output of 7 HP with an armature current of 38 A. The armature winding is wave connected and it has 690 conductors. Its armature resistance is 0.3 and drop at each brush is 1 V. Find (i) Useful torque, (ii) Total torque, (iii) Useful flux per pole and (iv) Rotational losses occurring in the motor. [ 1HP= 746 W]