DC Generators MCQ Questions Answers – Electrical Engineering
1) The brush voltage drop in a d.c. machine is about …………
a) 0.1 V
b) 10 V
c) 2 V
d) 20 V
2) Small d.c. machines generally have ………poles.
a) 4
b) 6
c) 2
d) 8
3) …….. d.c. machines are most common.
a) 2-pole
b) 4-pole
c) 6-pole
d) 8-pole
4) A triplex wave winding will have ……… parallel paths.
a) 6
b) 2
c) 4
d) none of the above
5) High-voltage d.c. machines use …….. winding.
a) lap
b) wave
c) either lap or wave
d) none of the above
6) The yoke of a d.c. machine carries ,…….. pole flux.
a) the
b) one-half of the
c) two times the
d) none of the above
7) The commutator pitch for a simplex lap winding is equal to …….
a) number of poles of the machine
b) pole pairs
c) 1
d) none of the above
8) The greatest percentage of heat loss in a d.c. machine is due to ……….
a) eddy current loss
b) hysteresis loss
c) copper loss
d) frictional loss
9) The armature conductors of 6-pole, lap wound d.c. generator are divided into
a) 2 parallel paths
b) 4 parallel paths
c) 3 parallel paths
d) 6 parallel paths
10) Hysteresis loss in a d.c. machine is directly proportional to ……….
a) speed
b) (speed)2
c) (speed)6
d) none of the above
11) The greatest percentage of heat loss in a d.c. machine is due to ,……..
a) eddy current loss
b) hysteresis loss
c) copper loss
d) frictional loss
12) The filed winding of a d.c. shunt machine usually carries …… of the rated current of the machine.
a) 2% to 5%
b) 15 % to 20%
c) more than 20%
d) less than 0.5%
13) The commutator of a d.c. generator acts as
a) an amplifier
b) a rectifier
c) a load
d) none of the above
14) The armature copper loss in a d.c. generator is a
a) constant loss
b) variable loss
c) stray loss
d) none of the above
15) The ideal commutation in a coil is not possible because each coil has
a) resistance
b) inductance
c) capacitance
d) none of the above
16) The commutator in a d.c. machine can convert
a) a.c. to d.c.
b) d.c. to a.c.
c) both (i) and (ii)
d) none of the above
17) Fleming’s right hand rule is applicable to
a) d.c. motor
b) alternator
c) transformer
d) d.c. generator