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.Management Sciences
Category: Electrical Machine Design
In induction motors, the length of air gap in kept as small as mechanically possible is order to have____________?
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A. low power factor
B. high power factor
C. high over load capacity
D. any of the above
The operation of a D.C. machine with large air gap lengths is comparatively_____________?
A. quiet
B. noisy
C. either of the above
D. none of the above
In D.C. machines, ir order to prevent excessive distortion of field form by the armature reaction, the field mmf must be made____________?
A. equal to that of armature mmf
B. less in comparison with the armature mmf
C. large in comparison with the armature mmf
D. none of the above
Aluminium when adopted as a conductor material in __________ transformers, decreases the overall cost of the transformer?
A. small size
B. medium size
C. large size
D. any of the above size
The resistivity of water should not be less than_____________?
A. 10 Q m
B. 100 Q m
C. 1000 Q m
D. 2000 Q m
In D.C. machines the number of slots per pole usually lies___________?
A. between 2 to 4
B. between 6 to 8
C. between 9 to 16
D. between 20 to 30
D.C. windings are____________?
A. sometimes 2-layer type
B. never 2-layer type
C. always 2-layer type
D. none of the above
Multiple inlet system of air cooling of turbo-alternators can be used for machines of rating upto_______________?
A. 10 MW
B. 30 MW
C. 60 MW
D. 150 MW
In a D.C. machine, the value of peripheral speed should not, normally, exceed___________?
A. 10 m/s
B. 20 m/s
C. 30 m/s
D. 40 m/s
When the two coil sides forming a coil are spaced exactly one pole pitch apart they are said to be of_____________?
A. short pitch
B. full pitch
C. either of the above
D. none of the above
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