A. only if the resistance of the field circuit is less than critical value
B. only if the resistance of the field circuit is greater than critical value
C. irrespective of the value of the resistance in the field circuit
D. none
Related Mcqs:
- A series generator can self-excite:______________?
A. only if the load current is zero
B. only if the load current is not zero
C. irrespective of the value of load current
D. none of the above - 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 - 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 - The e.m.f. induced in the armature of a shunt generator is 600 V. The armature resistance is 0.1 ohm. If the armature current is 200 A, the terminal voltage will be_____________?
A. 640 V
B. 620 V
C. 600 V
D. 580 V - A cumulatively compounded long shunt generator when operating as a motor would be____________?
A. cumulatively compounded long shunt
B. deferentially compounded long shunt
C. cumulatively compounded short shunt
D. differentially compounded short shunt - A shunt generator running at 1000 r.p.m. has generated e.m.f. as 200 V. If the speed increases to 1200 r.p.m., the generated e.m.f. will be nearly_______________?
A. 150 V
B. 175 V
C. 240 V
D. 290 V - The terminal voltage of a D.C. shunt generator drops on load because of all of the following reasons except:_____________?
A. armature reaction
B. armature resistance drop
C. field weakening due to armature reaction and armature
D. commutation - A sinusoidal voltage of 5 Hz is applied to the field of a shunt generator. The armature voltage wave will_____________?
A. will be zero
B. will be of 5 Hz
C. will be of 5 xiVHz
D. will be of v Hz 5 - The series field of a short-shunt D.C. generator is excited by_______________?
A. external current
B. armature current
C. shunt current
D. load current - 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
