Hi friends, lets check out some questions on dc generators which are asked in IES and Gate. Check out this objective questions on electrical engineering.
1) In dc machines, the interpoles are provided
A) for mechanical balancing of machines
B) to counteract the demagnetizing effect of armature mmf in the commutating zone
C) to counteract the reactance voltage and the cross-magnetizing effect of armature mmf in the commutating zone
D) to make commutation sparkless
E) both (C) and (D)
Ans:E
2) The commutating flux produced by interpole must be proportional to
A) armature current
B) field current
C) both armature and field currents
D) none of the above
Ans:A
3) The polarity of the interpole is the
A) same as that of main pole ahead in case of generators
B) same as that of main pole ahead in case of motors
C) same as that of main pole behind in case of motors
D) same as that of main pole behind in case of generators
E) both (a) and (c)
Ans:E
4) The interpole air gap is ........... that under the field poles in dc machines
A) smaller than
B) larger than
C) equal to
D) none of these
Ans: B
5) A dc machine is provided with both interpole and compensating winding. These two winding with respect to armature circuit will be in
A) series
B) parallel
C) former in series and the latter in parallel
D) former in parallel and the latter in series
Ans:A
6) The mmf necessary for establishment of flux in the magnetic circuit of a dc generator can be obtained by means of field coils excited by
A) some separate source
B) the generator itself
C) either of the above methods
D) none of these
Ans:C
7) In a separately excited dc generator the field is connected
A) in series with an armature
B) across the armature
C) to an external supply source
D) none of the above
Ans:C
8) Series field winding of a dc machine consists of
A) few turns of thick wire
B) few turns of thin wire
C) many turns of thick wire
D) many turns of thin wire
Ans:A
9) The series field of a short shunt dc generator is excited by ...............current
A) armature
B) shunt field
C) load
D) IL+Ish
Ans:C
10) When the shunt field of a dc compound generator is connected across both the series field and armature. such a connection is known as
A) short shunt
B) long shunt
C) cumulative compounding
D) differential compounding
Ans:B
If you have any doubts you can refer this posts...
1) In dc machines, the interpoles are provided
A) for mechanical balancing of machines
B) to counteract the demagnetizing effect of armature mmf in the commutating zone
C) to counteract the reactance voltage and the cross-magnetizing effect of armature mmf in the commutating zone
D) to make commutation sparkless
E) both (C) and (D)
Ans:E
2) The commutating flux produced by interpole must be proportional to
A) armature current
B) field current
C) both armature and field currents
D) none of the above
Ans:A
3) The polarity of the interpole is the
A) same as that of main pole ahead in case of generators
B) same as that of main pole ahead in case of motors
C) same as that of main pole behind in case of motors
D) same as that of main pole behind in case of generators
E) both (a) and (c)
Ans:E
4) The interpole air gap is ........... that under the field poles in dc machines
A) smaller than
B) larger than
C) equal to
D) none of these
Ans: B
5) A dc machine is provided with both interpole and compensating winding. These two winding with respect to armature circuit will be in
A) series
B) parallel
C) former in series and the latter in parallel
D) former in parallel and the latter in series
Ans:A
6) The mmf necessary for establishment of flux in the magnetic circuit of a dc generator can be obtained by means of field coils excited by
A) some separate source
B) the generator itself
C) either of the above methods
D) none of these
Ans:C
7) In a separately excited dc generator the field is connected
A) in series with an armature
B) across the armature
C) to an external supply source
D) none of the above
Ans:C
8) Series field winding of a dc machine consists of
A) few turns of thick wire
B) few turns of thin wire
C) many turns of thick wire
D) many turns of thin wire
Ans:A
9) The series field of a short shunt dc generator is excited by ...............current
A) armature
B) shunt field
C) load
D) IL+Ish
Ans:C
10) When the shunt field of a dc compound generator is connected across both the series field and armature. such a connection is known as
A) short shunt
B) long shunt
C) cumulative compounding
D) differential compounding
Ans:B
If you have any doubts you can refer this posts...
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