Electrical Machines
The magnetic field which initially induces emf in the armature in a self excited DC generator is because of

  permanent magnets.
None of these
 armature reaction.
  residual magnetism.

ANSWER DOWNLOAD EXAMIANS APP

Electrical Machines
If two 8-pole dc machines of identical armature sare wound, one with lap winding and the other with wave winding, then

 lap-wound machine will have more rated voltage and more current
 wave-wound machine will have more rated voltage and less current
 lap-wound machine will have more rated voltage and less current
 wave-wound machine will have more rated current and more voltage

ANSWER DOWNLOAD EXAMIANS APP