Electrical Machines
The residual magnetism of a self-excited dc generator is lost. To build up its emf again

 the field winding connection must be reversed
 field winding must be excited by low voltage dc supply
 the field winding must be replaced
 the armature connection must be reversed

ANSWER DOWNLOAD EXAMIANS APP

Electrical Machines
The compensating winding in a DC machine

 is located in armature slots for compensation of the armature reaction.
  is located on pole shoes for avoiding the flashover at the commutator.
 is located on commutating poles for improving commutation.
  is located on pole shoes to avoid the sparking at the brushes.

ANSWER DOWNLOAD EXAMIANS APP

Electrical Machines
In a step down transformer which one of the following statements is true?

 Number of secondary turns is more than that of primary.
  Number of secondary turns is less than primary turns.
 Secondary power is less than primary power.
 Secondary current is less than primary current.

ANSWER DOWNLOAD EXAMIANS APP