Electrical Machines
which of the following type of brush and their application is/are correct

 carbon brush → normal ratings
All of these
 copper graphite → low voltage high current density
 electro graphite → large ratings

ANSWER DOWNLOAD EXAMIANS APP

Electrical Machines
Compensating windings are used in DC generators

None of these
  to provide path for the circulation of cooling air.
  to neutralize the cross magnetizing effect of the armature reaction.
  mainly to reduce the eddy currents by providing local short circuit.

ANSWER DOWNLOAD EXAMIANS APP