Top 150+ Solved DC Generators MCQ Questions Answer
Q. The insulating material used between the commutator segments is normally
a. graphite
b. paper
c. mica
d. insulating varnish
Q. In D.C. generators, the brushes on commutator remain in contact with conductorswhich
a. lie under south pole
b. lie under north pole
c. lie under interpolar region
d. are farthest from the poles
Q. If brushes of a D.C. generator are moved in order to bring these brushes in magneticneutral axis, there will be
a. demagnetisation only
b. cross magnetisation as well as magnetisation
c. crossmagnetisation as well as demagnetising
d. cross magnetisation only
Q. Armature reaction of an unsaturated D.C. machine is
a. crossmagnetising
b. demagnetising
c. magnetising
d. none of above
Q. D.C. generators are connected to the busbars or disconnected from them only under thefloating condition
a. to avoid sudden loading of the primemover
b. to avoid mechanicaljerk to the shaft
c. to avoid burning of switch contacts
d. all above
Q. Eddy currents are induced in the pole shoes of a D.C. machine due to
a. oscillating magnetic field
b. pulsating magnetic flux
c. relative rotation between field and armature
d. all above
Q. Equilizer rings are required in case armature is
a. wave wound
b. lap wound
c. delta wound
d. duplex wound
Q. Welding generator will have
a. lap winding
b. wave winding
c. delta winding
d. duplex wave winding
Q. In case of D.C. machine winding, number of commutator segments is equal to
a. number of armature coils
b. number of armature coil sides
c. number of armature conductors
d. number of armature turns
Q. For a D.C. machines laboratory following type of D.C. supply will be suitable
a. rotary converter
b. mercury are rectifier
c. induction motor D.C. generator set
d. synchronous motor D.C. generator set
Q. The function of pole shoes in the case of D.C. machine is
a. to reduce the reluctance of the magnetic path
b. to spread out the flux to achieve uniform flux density
c. to support the field coil
d. to discharge all the above functions
Q. In the case of lap winding resultant pitch is
a. multiplication of front and back pitches
b. division of front pitch by back pitch
c. sum of front and back pitches
d. difference of front and back pitches
Q. Which of the following statement about D.C. generators is false ?
a. Compensating winding in a D.C. machine helps in commutation
b. In a D. C. generator interpoles winding is connected in series with the armature winding
c. Back pitch and front pitch are both odd and approximately equal to the pole pitch
d. Equilizing bus bars are used with parallel running of D.C. shunt generators