Top 150+ Solved DC Generators MCQ Questions Answer
Q. The voltage drop for which of the following types of brush can be expected to beleast?
a. Graphite brushes
b. Carbon brushes
c. Metal graphite brushes
d. None of the above
Q. Open circuited armature coil of a D.C. machine is
a. identified by the scarring of the commutator segment to which open circuited coil is connected
b. indicated by a spark completely around the commutator
c. both (a) and (b)
d. none of the above
Q. For the parallel operation of two or more D.C. compound generators, we should ensure that
a. voltage of the incoming generator should be same as that of bus bar
b. polarity of incoming generator should be same as that of bus bar
c. all the series fields should be run in parallel by means of equilizer connection
d. series fields of all generators should be either on positive side or negative side of the armature
Q. D.C. series generator is used
a. to supply traction load
b. to supply industrial load at constant voltage
c. voltage at the toad end of the feeder
d. for none of the above purpose
Q. Following D.C. generator will be in a position to build up without any residual magnetism in the poles
a. series generator
b. shunt generator
c. compound generator
d. self-excited generator
Q. Interpole flux should be sufficient to
a. neutralise the commutating self induced e.m.f.
b. neutralise the armature reaction flux
c. neutralise both the armature reaction flux as well as commutating e.m.f. induced in the coil
d. perform none of the above functions
Q. D.C. generator generally preferred for charging automobile batteries is
a. series generator
b. shunt generator
c. long shunt compound generator
d. any of'the above
Q. In a D.C. generator the number of mechanical degrees and electrical degrees will be thesame when
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
Q. In D.C. generators the polarity of the interpoles
a. is the same as that of the main pole ahead
b. is the same as that of the immediately preceding pole
c. is opposite to that of the main pole ahead
d. is neutral as these poles do not play part in generating e.m.f.
Q. 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
Q. In a D.C. generator in order to reduce sparking at brushes, the self-induced e.m.f. in thecoil is neutralised by all of the following except
a. interpoles
b. dummy coils
c. compensating winding
d. shifting of axis of brushes
Q. In D.C. generators on no-load, the air gap flux distribution in space is
a. sinusoidal
b. triangular
c. pulsating
d. flat topped