A dc, separately excited motor is connected to a fan-type load. The armature circuit of the motor is connected to a full-wave, ac/dc SCR converter. The input voltage to the converter is 200 V (rms). The triggering angle of the converter is adjusted for a motor speed of 500 rpm. The armature current in this case is 16 A. The armature resistance of the motor is 0.5? , and the field constant (K? ) is 2.5

a. Calculate the triggering angle to run the motor at 500 rpm.
b. If the motor speed is to be reduces to 100 rpm, what is the triggering angle?


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