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
D.C. Generators
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 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
A sinusoidal voltage of 5 Hz is applied to the field of a shunt generator. The armature voltage wave will_____________?
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 purpose of providing dummy coils in a generator is____________?
The purpose of providing dummy coils in a generator is____________?
A. to reduce eddy current losses
B. to enhance flux density
C. to amplify voltage
D. to provide mechanical balance for the rotor
In D.C. generators on no-load, the air gap flux distribution in space is______________?
In D.C. generators on no-load, the air gap flux distribution in space is______________?
A. sinusoidal
B. triangular
C. pulsating
D. flat topped
The terminal voltage of a D.C. shunt generator drops on load because of all of the following reasons except:_____________?
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
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______________?
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
In a D.C. generator the magnetic neutral axis coincides with the geometrical neutral axis, when_______________?
In a D.C. generator the magnetic neutral axis coincides with the geometrical neutral axis, when_______________?
A. there is no load on|he generator
B. the generator runs on full load
C. the generator runs on overload
D. the generator runs on designed speed
In a level compounded D.C. generator, full load terminal voltage is______________?
In a level compounded D.C. generator, full load terminal voltage is______________?
A. negligibly low
B. equal to no-load terminal voltage
C. more than no-load terminal voltage
D. less than no-load terminal voltage
The e.m.f. generated in a D.C. generator is directly proportional to____________?
The e.m.f. generated in a D.C. generator is directly proportional to____________?
A. flux/pole
B. speed of armature
C. number of poles
D. all of the above