A. copper lugs
B. resistance wires
C. insulation pads
D. brazing
0
Which of the following could be lamina-proximately the thickness of laminations of a D.C. machine ?
0
Laminations of core are generally made of________________?
A. 0.005 mm
B. 0.05 mm
C. 0.5 m
D. 5 m
0
The armature of D.C. generator is laminated to_______________?
A. case iron
B. carbon
C. silicon steel
D. stainless steel
0
Iron losses in a D.C. machine are independent of variations in_____________?
A. reduce the bulk
B. provide the bulk
C. insulate the core
D. reduce eddy current loss
0
Iron losses in a D.C. machine are independent of variations in______________?
A. speed
B. load
C. voltage
D. speed and voltage
0
In D.C. generators, current to the external circuit from armature is given through_____________?
A. speed
B. load
C. voltage
D. speed and voltage
0
Brushes of D.C. machines are made of_________?
A. commutator
B. solid connection
C. slip rings
D. none of above
0
If a D.C. generator fails to build up the probable cause could not be_____________?
A. carbon
B. soft copper
C. hard copper
D. all of above
0
If B is the flux density, I the length of conductor and v the velocity of conductor, then induced e.m.f. is given by______________?
A. imperfect brush contact
B. field resistance less than the critical resistance
C. no residual magnetism in the generator
D. faulty shunt connections tending to reduce the residual magnetism
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