Electrical Machines
A 230 volt dc motor has an armature winding resistance of 0.5 ohm. Calculate the emf induced by the motor if the full load armature current is 23 ampere.

  218.5 volt.
  None of these.
  120 volt.
 220.4 volt.

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Electrical Machines
The results of a slip test for determining direct axis (Xd) and quadrature axis (Xq) reactances of a star connected salient pole alternator are given below Phase values: Vmax = 108 V ; Vmin = 96 V Imax = 12 A ; Imin = 10 A Hence the two reactances will be

 Xd = 9.6Ω and Xq = 9Ω
 Xd = 10.8Ω and Xq = 8Ω
 Xd = 8Ω and Xq = 10.8Ω
 Xd = 9Ω and Xq = 9.6Ω

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Electrical Machines
In case of 3 - Φ IM, plugging means

  pulling the motor directly on line without a rotor.
  interchanging two supply phases for quick stopping.
  starting the motor on load which is more than the rated load.
  locking of rotor due to harmonics.

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