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.Management Sciences
Category: Electrical Machine Design
Which of the following brushes can be used for high values of current density ?
A. Metal graphite brushes
B. Hard carbon brushes
C. Electro-graphitic brushes
D. Natural graphite brushes
Which of the following methods is most accurate ?
A. Equivalent current method
B. Equivalent power method
C. Equivalent torque method
D. Method of average losses
The high voltage winding is usually which of the following type ?
A. Cylindrical winding with circular conductors
B. Cross-over winding with either circular or small rectangular conductors
C. Continuous disc type winding with rectangular conductors
D. All of the above types
____________are always double layer type?
A. Closed windings
B. Open windings
C. Either of the above
D. None of the above
The change in flux linkages can be caused in which of the following ways ?
A. The flux is constant with respect to time and is stationary and the coil moves through it
B. The coil is stationary with respect to flux and the flux varies in magnitude with respect to time
C. Both the changes mentioned above occur together, i.e., the coil moves through a time varying field
D. All of the above
The value of exciting or magnetizing current depends upon which of the following factors ?
A. Total m.m.f. required
B. The number of turns in the exciting winding
C. The way in which the winding is distributed
D. All of the above
Transformers with a capacity of up to __________ have a cooling radiator system with natural cooling?
A. 2 MVA
B. 5 MVA
C. 7.5 MVA
D. 10 MVA
Commercial available medium size machines have a speed range of __________ ?
A. 200 to 400 r.p.m
B. 600 to 1000 r.p.m
C. 1000 to 1500 r.p.m
D. 2000 to 2500 r.p.m
Which of the following in an application of D.C. motors?
A. Traction
B. Drives for process industry
C. Battery driven vehicles
D. Automatic control
E. All of the above
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