Top 350+ Solved Electrical Machine 1 MCQ Questions Answer
Q. The type of D.C. motor used for shears and punches is
a. shunt motor
b. series motor
c. differential compoutid D.C. motor
d. cumulative compound D.C. motor
Q. If a D.C. motor is connected across the A.C. supply it will
a. run at normal speed
b. not run
c. run at lower speed
d. burn due to heat produced in the field winding by .eddy currents
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
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. shuntmotors
Q. In a D.C. shunt motor, under the conditions of maximum power, the current inthearmature 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 confirmedthat a particularmotor is D.C. motor?
a. Frame
b. Shaft
c. Commutator
d. Stator
Q. In which of the following applications D.C. series motor is invariably tried?
a. Starter for a car
b. Drive for a water pump
c. Fan motor
d. Motor operation in A.C. or D.C.
Q. In D.C. machines fractional pitch winding is used
a. to improve cooling
b. to reduce copper losses
c. to increase the generated e.m.f.
d. to reduce the sparking
Q. A three point starter is considered suitable for
a. shunt motors
b. shunt as well as compound motors
c. shunt, compound and series motors
d. all D.C. motors