Electrical Machines
In Ward-Leonard system, the lower limit of the speed imposed by

 Armature resistance.
 Residual magnetism of the generator.
 None of above.
 Field resistance.

ANSWER DOWNLOAD EXAMIANS APP

Electrical Machines
In a dc generator operating on load with its brushes on the geometrical neutral axis (GNA), the magnetic neutral axis (MNA) is shifted in the direction of rotation. Now, if the brushes are given a lead of 90° (electrical), then the MNA will

 shift forward by 90°
 coincide with the GNA
 shift forward by less than 90°
 shift forward by more than 90°

ANSWER DOWNLOAD EXAMIANS APP

Electrical Machines
The mmf produced by rotor currents of a 3 - Φ induction motor

  is at standstill with respect to stator mmf.
  rotates at the speed of rotor in the air gap.
  rotates at synchronous speed with respect to rotor.
  rotates at slip speed with respect to stator mmf.

ANSWER DOWNLOAD EXAMIANS APP

Electrical Machines
A belt-driven cumulatively-compound dc generator is delivering power to the dc mains. If the Belt snaps then the machine will run as a

 cumulative compounded motor in opposite direction
 cumulative compounded motor in the same direction
 differentially compounded motor in the same direction
 differentially compounded motor in the opposite direction

ANSWER DOWNLOAD EXAMIANS APP