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.Management Sciences
Category: D.C. Generators
Number of tappings for each equalizer ring is equal to_____________?
A. number of pole pairs
B. number of poles
C. number of parallel paths
D. number of commutator segments
The bearings used to support the rotor shafts are generally______________?
A. ball bearings
B. bush bearings
C. magnetic bearmgs
D. needle bearings
Which of the following generating machine will offer constant voltage on all loads?
A. Self-excited generator
B. Separately excited generator
C. Level compounded generator
D. All of the above
For a D.C. generator when the number of poles and the number of armature conductors is fixed, then which winding will give the higher e.m.f___________ ?
A. Lap winding
B. Wave winding
C. Either of A. and B. above
D. Depends on other features of design
The critical resistance of the D.C. generator is the resistance of_____________?
A. field
B. brushes
C. armature
D. load
Armature reaction in a generator results in_____________?
A. demagnetisation of leading pole tip and magnetisation of trailing pole tip
B. demagnetisation of trailing pole tip and magnetisation of leading pole tip
C. damagnetising the center of all poles
D. magnetising the center of all poles
In a D.C. generator the critical resistance can be increased by_____________?
A. increasing its field resistance
B. decreasing its field resistance
C. increasing its speed
D. decreasing its speed
The rapid wear of brushes takes place due to____________?
A. abrasion from dust
B. excessive spring pressure
C. rough commutator bars
D. high mica insulation between com-mutation bars
E. all of the above factors
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