Electrical Machines
Which of the following DC motors has almost constant speed over their full load range?

 Series.
 Compound (cummolative).
  Shunt.
 none of these.

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Electrical Machines
Consider the following statements regarding the speed control of dc motors : 1. ward-leonard method is suitable forconstant-torque drives 2. Ward-leonard method is suitable for constant-power drives 3. field-control method facilitates speed control below base speed 4. Armature-resistance control method is more efficient than ward-leanard method 5. Field-control method is suitable for constant-torque drives 6. Armature-resistance control method is suitable for constant-torque drives From these, the correct answer is

 1, 3, 5
 1, 2, 5
 1, 2, 6
 1, 4, 6

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Electrical Machines
In large sized DC machines the compensating windings are provided to

 reduce eddy current losses by providing local short circuits.
 compensate for the decrease in speed due to increase of load.
None of these
  neutralize voltage induced in coil due to fluctuation of l

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Electrical Machines
The factors that are responsible for decrease in terminal voltage of a shunt generator are

  reduction in field current, effect of armature reaction, armature.
  armature resistance, effect of armature reaction.
 armature resistance, effect of armature reaction.
 armature resistance, inter poles, armature.

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