A. speed
B. load
C. voltage
D. speed and voltage
Related Mcqs:
- Iron losses in a D.C. machine are independent of variations in_____________?
A. speed
B. load
C. voltage
D. speed and voltage - In case of D.C. machines, mechanical losses are primary function of____________?
A. current
B. voltage
C. speed
D. none of above - Copper brushes in D.C. machine are used_____________?
A. where low voltage and high currents are involved
B. where high voltage and small cur-rents are involved
C. in both of the above cases
D. in none of the above cases - Which of the following could be lamina-proximately the thickness of laminations of a D.C. machine ?
A. 0.005 mm
B. 0.05 mm
C. 0.5 m
D. 5 m - Armature reaction of an unsaturated D.C. machine is_____________?
A. crossmagnetising
B. demagnetising
C. magnetising
D. none of above - Eddy currents are induced in the pole shoes of a D.C. machine due to______________?
A. oscillating magnetic field
B. pulsating magnetic flux
C. relative rotation between field and armature
D. all above - The function of pole shoes in the case of D.C. machine is______________?
A. to reduce the reluctance of the mag¬netic path
B. to spread out the flux to achieve uniform flux density
C. to support the field coil
D. to discharge all the above functions - To avoid formation of grooves in the commutator of a D.C. machine?
A. the brushes of opposite polarity should track each other
B. the brushes of same polarity should track each other
C. brush position has no effect on the commutator grooving
D. None - In any rotating machine that part which houses the conductors and in which e.m.f. induced is to be utilized is called____________?
A. rotor
B. stator
C. field
D. armature - Following energized winding of a D.C. machine should not be opened as it would produce high inductive voltage which may be dangerous to personnel and may cause its own insulation failure.
A. Series field
B. Compensating field
C. Inter pole field
D. Shunt field
