A 205 V, 19 kW dc shunt motor has a 3 step (3 resistance) starter that restricts the starting armature current between its rated value and some K times this rated value. This motor is 69 % efficient at rated conditions and its field resistance = 205 ohms. The starting resistance in each step is 6 times its armature resistance.
What is the maximum starting armature current in A?
What is total resistance of the starter in Ohms?
What is the back EMF in Volts, when the starter is just put in 2nd step? Assume that the transition from 1st to 2nd step is instantaneous.
What is the back EMF in Volts by the end of the 2nd step?
What is the back EMF of this motor in Volts under rated conditions?
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