1. . The purpose of a brush in a DC machine is to ________.
(A) collect voltage from the commutator
(B) collect current from the commutator
(C) to provide interaction between the segments of commutator
(D) clean the commutator
2. . A coil consists of _________.
(A) two coil sides
(B) two conductors
(C) two turns
(D) four turns
3. . A DC generator converts ________ energy to ________ energy.
(A) Electrical, Mechanical
(B) Mechanical, Electrical
(C) Mechanical, Chemical
(D) Electrical, Power
4. . ________ is induced in every generator.
(A) AC
(B) DC
(C) Pulsating DC
(D) RMS
5. . Commutator converts _________ into _________.
(A) AC, DC
(B) DC, AC
(C) AC, Square wave
(D) DC, PWM
6. . To make the AC as unidirectional _________ is used.
(A) Split ring
(B) Slip ring
(C) both a & b
(D) none
7. . The yoke is _________.
(A) Not laminated
(B) laminated
(C) either a or b
(D) None
8. . The yoke is _______ of DC machine.
(A) Base
(B) Structure
(C) Frame
(D) All
9. . Yoke provides minimum _________ to magnetic flux.
(A) Resistance
(B) Conductance
(C) Reluctance
(D) Inductance
10. . Yoke is made of _________.
(A) Wrought iron
(B) Cast iron
(C) Pig iron
(D) Cast steel
11. . Pole core is placed ________ to yoke.
(A) Top
(B) Interior
(C) Bottom
(D) Exterior
12. . Pole core is always _______ in numbers.
(A) Odd
(B) Even
(C) Differential
(D) Commulative
13. . Pole shoes ______ the flux in air gap.
(A) Repel
(B) Concentrate
(C) Attract
(D) Spread
14. . Pole shoes supports the _______ coils.
(A) Armature
(B) Field
(C) Commutation
(D) Conductor
15. . Pole cores are made _________.
(A) Sometimes laminated
(B) Not laminated
(C) Laminated
(D) None
16. . Field coils are made according to the size of ________.
(A) Main poles
(B) Pole cores
(C) Rotor
(D) Armature
17. . The additional poles placed between the main poles are ________.
(A) Inter poles
(B) Field poles
(C) Sub poles
(D) All
18. . The rotating cylindrical part inside the DC machine is _________.
(A) Commutator
(B) Armature
(C) Carbon brush
(D) Stator
19. . The thickness of armature stampings is up to ________ mm.
(A) 0.1
(B) 0.2
(C) 0.5
(D) 1
20. . There are ________ inside the armature stampings.
(A) Slots
(B) Field poles
(C) Field coils
(D) All
21. . There are ________ types of DC generator regarding field excitation.
(A) 2
(B) Any of all
(C) 6
(D) 3
22. . There are _______ important characteristics of DC generator.
(A) 2
(B) 5
(C) 3
(D) 6
23. . Compound generators are of ________ types.
(A) Three
(B) Two
(C) Four
(D) None