Electrical Machines
Which of the following factors improve commutation in a dc machine ? 1. High contact resistance of brushes 2. High inductance of the coils undergoing commutation 3. Shifting of brushes in the direction of rotation for a generator and in the opposite direction For a motor 4. Narrow width for the commutation bars Select the correct answer using the codes given below : Codes :

 2, 3 and 4
 1, 2 and 4
 1 and 3
 1, 2, and 3

ANSWER DOWNLOAD EXAMIANS APP

Electrical Machines
DC Motor

  dc shunt motor with field weakening.
  dc compound motor.
  dc series motor.
  dc shunt with armature resistance control.

ANSWER DOWNLOAD EXAMIANS APP