Electrical Machines
In a DC machine the armature mmf is

  stationary with respect to armature.
  rotating with respect to field poles as well as armature.
 rotating with respect to field poles.
  stationary with respect to field poles.

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Electrical Machines
Armature reaction in a DC machine

 makes an angle with the main pole axis which is load dependent.
 is in direct opposition to the main poles.
  makes an angle of 90° with the main pole axis.
 is in the same direction as the main poles.

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