The armature of a 230 Volts shunt motor has a resistance of 0.18 ohm. A resistance is inserted in series with the armature at the instant of starting so as not to exceed 76 Amp at starting. calculate the value to which this resistance can be reduced when the armature accelerates until Ec is 168 volts. Brush drop is 2 Volts.

9. Which type of motor is most widely used as servomotor today? a) induction motor b) DC brush motor c) step motor d) permanent magnet AC motor

determine "A" through "G" for the DC motor on worksheet 5 when it is running at capacity and its specification are as follows rated input   125volt    16 amp armature resist.     0.3 ohms shunt field resist    50  ohm series field resist.      .6  ohm rheostat resist.        12.5   ohm   . power consumed by armature resistance   a-  54.68 W b-  312.5 W c-  1632.83 W d-  2000  W