DC Machine (Motor Generator) MCQ Quiz Online Mock Test 

|| DC Machine (Motor) MCQ Online Mock Test  || DC Machine MCQ Mock test || DC Machine MCQ || DC Machine Quiz || DC Motor MCQ ||

 Q-: 1) The MMF produced by interpole is proportional to

A) Field current

B) Armature current

C) Armature voltage

D) 1/field current

Q-: 2) A lap wound dc generator having 250 armature conductors runs at 1200 rpm. if the generated emf is 200V then the operating flux of the dc generator is  

A) 0.8 Wb

B) 0.04 Wb

C) 0.06 Wb

D) 0.02 Wb

Q-: 3) The highest speed attainable by d.c. shunt motor is

A) Much higher than no-load speed

B) Much lower than no-load

C) Ideally infinite

D) Equally to no-load speed

Q-: 4) The direction of rotation of a d.c. shunt motor can be reversed by interchanging  

A) The armature terminals only

B)  Either field or armature terminals

C) The supply terminals.

D) The field terminals only

Q-: 5) Poles of d.c. machines are often laminated to reduce

A) Eddy current loss

B) Iron weight

C) Armature reaction

D) Hysteresis loss

Q-: 6) The Load characteristic of dc shunt generator is determined by

A) The voltage drop in armature resistance

B) The voltage drop due to armature reaction voltage drop due to decreased field current and voltage drop in armature resistance

C) The voltage drop due to armature reaction and voltage drop due to armature reaction voltage drop due to decreased field current and voltage drops in armature resistance and field resistance.

D) The voltage drop due to decreased field in armature resistance and field resistance

Q-: 7) If the supply polarity to the armature terminals of a separately excited d.c. motor is reversed the motor will run under.

A) Plugging condition

B) Regenerative braking condition

C) Dynamic braking condition

D) Normal motoring condition

Q-: 8) The Commutator in a d.c. machine act as

A) A mechanical inverter

B) A mechanical rectifier

C) current controller

D) either (a) or (b)

Q-: 9) The purpose of using dummy coil in D.C. machine is to

A) Eliminate harmonics developed in the machine

B) Eliminate armature reaction

C) Bring mechanical balance of armature

D) Bring mechanical balance of the body motor.

Q-: 10) For a 6-pole D.C. machine with wave wound armature, the number of brushes required is

A) 2

B) 4

C) 6

D) 12