(a) Shunt motor
(b) Series motor
(c) Cumulative compound motor
(d) Differentiate compound motor
Ans. (b) Series motor
Q.2. The direction of rotation of a D.C. series motor can be changed by
(a) Interchanging supply terminals
(b) Interchanging field terminals
(c) Either of (a) and (b) above
(d) None of the above
Ans. (b) Interchanging field terminals
Q.3. Which of the following application requires high starting torque?
(a) Lathe machine
(b) Centrifugal pump
(c) Locomotive
(d) Air blower
Ans. (c) Locomotive
Q.4. If a D.C. motor is to be selected for conveyors, which rotor would be preferred?
(a) Series motor
(b) Shunt motor
(c) Differentially compound motor
(d) Cumulative compound motor
Ans. (a) Series motor
Q.5. Which D.C. motor will be preferred for machine tools?
(a) Series motor
(b) Shunt motor
(c) Cumulative compound motor
(d) Differential compound motor
Ans. (b) Shunt motor
Q.6. Differentially compound D.C. motors can find applications requiring
(a) High starting torque
(b) Low starting torque
(c) Variable speed
(d) Frequent on-off cycles
Ans. (b) Low starting torque
Q.7. Which D.C. motor is preferred for elevators?
(a) Shunt motor
(b) Series motor
(c) Differential compound motor
(d) Cumulative compound motor
Ans. (d) Cumulative compound motor
Q.8. 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
(d) The motor will continue to constant speed
Ans. (c) The motor will attain dangerously high speed
Q.9. 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. while starting
Ans. (d) To restrict armature current as there is no back e.m.f. while starting
Q.10. A D.C. series motor is that which
(a) Has its field winding consisting of thick wire and less turns
(b) Has a poor torque
(c) Can be started easily without load
(d) Has almost constant speed
Ans. (a) Has its field winding consisting of thick wire and less turns
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