In a D.C. machine stray loss is the sum of_____________?
(A) total copper loss and mechanical loss
(B) armature copper loss and iron loss
(C) shunt field copper loss and mechanical loss
(D) iron loss and mechanical loss
The armature core of a D.C. generator is usually made of__________________?
(A) silicon steel
(B) copper
(C) non-ferrous material
(D) cast-iron
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
The e.m.f. generated by a shunt wound D.C. generator isE. Now while pole flux remains constant, if the speed of the generator is doubled, the e.m.f. generated will be_______________?
(A) E/2
(B) 2E
(C) slightly less than E
(D) E
A D.C. generator can be considered as____________?
(A) rectifier
(B) primemover
(C) rotating amplifier
(D) power pump
The voltage drop for which of the following types of brush can be expected to be least ?
(A) Graphite brushes
(B) Carbon brushes
(C) Metal graphite brushes
(D) None of the above
Two generators A and B have 6-poles each. Generator A has wave wound armature while generator B has lap wound armature. The ratio of the induced e.m.f. is generator A and B will be_______________?
(A) 2 : 3
(B) 3 : 1
(C) 3 : 2
(D) 1 : 3
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
In D.C. generators, lap winding is used for______________?
(A) high voltage, high current
(B) low voltage, high current
(C) high voltage, low current
(D) low voltage, low current
In a D.C. generator the ripples in the direct e.m.f. generated are reduced by_____________?
(A) using conductor of annealed copper
(B) using commutator with large number of segments
(C) using carbon brushes of superior quality
(D) using equiliser rings