Rheostatic braking is employed with a 4-pole dc separately excited motor driving a load. The armature is wave wound and has 251 conductors. The moment of inertia of the motor as well as the load is 350  kg-m^2. The resistance of the armature circuit winding is 0.02 ohm. Assuming that the flux per pole is constant at 0.02  Wb, calculate the time taken to reduce the speed from 100 rpm to 1 rpm. The maximum permissible armature current is 300  A and may be assumed to be constant until the entire ex