Top 150+ Solved DC Motor MCQ Questions Answer
Q. To get the speed of D.C, motor below the normal without wastage of electrical energyis used.
a. Ward Leonard control
b. rheostatic control
c. any of the above method
d. none of the above method
Q. When two D.C. series motors are connected in parallel, the resultant speed is
a. more than the normal speed
b. loss than the normal speed
c. normal speed
d. zero
Q. The speed of a D.C. shunt motor more than its full-load speed can be obtained by
a. decreasing the field current
b. increasing the field current
c. decreasing the armature current
d. increasing the armature current
Q. In a D.C. shunt motor, speed is
a. independent of armature current
b. directly proportional to the armature current
c. proportional to the square of the current
d. inversely proportional to the armature current
Q. A direct on line starter is used: for starting motors
a. iip to 5 H.P.
b. up to 10 H.P.
c. up to 15 H.P.
d. up to 20 H.P.
Q. What will happen if the back e.m.f. of a D.C. motor vanishes suddenly?
a. The motor will stop
b. The motor will continue to run
c. The armature may burn
d. The motor will run noisy
Q. In case of D.C. shunt motors the speed is dependent on back e.m.f. only because
a. back e.m.f. is equal to armature drop
b. armature drop is negligible
c. flux is proportional to armature current
d. flux is practically constant in D:C. shunt motors
Q. In a D.C. shunt motor, under the conditions of maximum power, the current in thearmature will be
a. almost negligible
b. rated full-load current
c. less than full-load current
d. more than full-load current
Q. These days D.C. motors are widely used in
a. pumping sets
b. air compressors
c. electric traction
d. machine shops
Q. By looking at which part of the motor, it can be easily confirmed that a particularmotor is D.C. motor?
a. Frame
b. Shaft
c. Commutator
d. Stator
Q. Differentially compound D.C. motors can find applicationsrequiring
a. high starting torque
b. low starting torque
c. variable speed
d. frequent on-off cycles
Q. If the field of a D.C. shunt motor gets opened while motor is running
a. the speed of motor will be reduced %
b. the armature current will reduce
c. the motor will attain dangerously high speed 1
d. the motor will continue to nuvat constantspeed
Q. Starters are used with D.C. motors because
a. these motors have high starting torque
b. these motors are not self-starting
c. back e.m.f. of these motors is zero initially
d. to restrict armature current as there is no back e.m.f. whilestarting
Q. A D.C. series motor is that which
a. has its field winding consisting of thick wire and lessturns
b. has a poor torque
c. can be started easily without load
d. has almost constant speed
Q. To get the speed of D.C, motor below the normal without wastage of electrical energy isused.
a. Ward Leonard control
b. rheostatic control
c. any of the above method
d. none of the above method