A 140 V, DC separately excited motor drives a constant-torque load at 1000 rpm speed. The armature and field resistances are 0.9 N and 145 N, respectively. The motor draws a lin current of 9 A at the given load and the field voltage is 115 V. Answer the following questio 1- Calculate the resistance that should be added Radd N to the armature circuit to Radd ww I reduce the speed by 90%. Radd 2- Calculate the efficiency of the motor without the added Radd N if the D. rotational losses is equal to 135.12 W. V. R. V

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Speed control of motor

Speed control by DC motor-speed controller is required to realize variable speed drive. Whenever a motor drives a particular load, it is called drive, and variable speed drive refers to a load requiring variable speed. All this is obtained by a DC motor speed controller.