A. r.p.m. is more than 300
B. r.p.m. is less than 300
C. number of poles is 4
D. number of poles is 2
Related Mcqs:
- 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 - Which of the following components of a D.C, generator plays vital role for providing direct current of a D.C. generator ?
A. Dummy coils
B. Commutator
C. Eye bolt
D. Equilizer rings - 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 - In case of D.C. machines, mechanical losses are primary function of____________?
A. current
B. voltage
C. speed
D. none of above - The field coils of D.C. generator are usually made of_____________?
A. mica
B. copper
C. cast iron
D. carbon - Flashing the field of D.C. generator means:______________?
A. neutralising residual magnetism
B. creating residual magnetism by a D.C. source
C. making the magnetic losses of forces parallel
D. increasing flux density by adding extra turns of windings on poles - In case of a flat compounded generator:
A. voltage generated is less than the rated voltage
B. generated voltage is proportional to the load on the generator
C. voltage remains constant irrespective of the load
D. speed varies in proportion to the load on the generator - In a D.C. generator in order to reduce sparking at brushes, the self-induced e.m.f. in the coil is neutralised by all of the following except______________?
A. interpoles
B. dummy coils
C. compensating winding
D. shifting of axis of brushes - A 220 V D.C. generator is run at full speed without any excitation. The open circuit voltage will be_____________?
A. zero
B. about 2 V
C. about 50 V
D. 220 V - As a result of armature reaction, the reduction in the total mutual air gap flux in a D.C. generator is approximately______________?
A. 40 percent
B. 25 percent
C. 10 percent
D. 5 percent
