The starting resistance of a D.C. motor is generally_______________?

Related Mcqs:

1. By looking at which part of the motor, it can be easily confirmed that a particular motor is D.C. motor?

   A. Frame
   B. Shaft
   C. Commutator
   D. Stator

2. Flywheel is used with D.C. compound motor to reduce the peak demand by the motor, compound motor will have to be_____________?

   A. level compounded
   B. under compounded
   C. cumulatively compounded
   D. differentially compounded

3. One D.C. motor drives another D.C. motor. The second D.C. motor when excited and driven_______________?

   A. runs as a generator
   B. does not run as a generator
   C. also runs as a motor comes to stop after sometime

4. For starting a D.C. motor a starter is required because___________?

   A. it limits the speed of the motor
   B. it limits the starting current to a safe value
   C. it starts the motor
   D. none of the above

5. For the same H.P. rating and full load speed, following motor has poor starting torque_____________?

   A. shunt
   B. series
   C. differentially compounded
   D. cumulativelyc’ompounded

6. Following motor is used where high starting torque and wide speed range control is required?

   A. Single phase capacitor start
   B. Induction motor
   C. Synchronous motor
   D. D.C. motor
   E. None of the above

7. As there is no back e.m.f. at the instant of starting a D.C. motor, in order to prevent a heavy current from flowing though the armature circuit____________________?

   A. a resistance is connected in series with armature
   B. a resistance is connected parallel to the armature
   C. armature is temporarily open circuited
   D. a high value resistor is connected across the field winding

8. Where D.C. motor of H.P. 12 or more requires frequent starting, stopping, reversing and speed control______________?

   A. drum type controller is used
   B. three point starter is used
   C. four point starter is used
   D. all above can be used

9. If the field winding resistance of a DC shunt motor is increases, its speed will____________?

   If the field winding resistance of a DC shunt motor is increases, its speed will
   A. decreases
   B. increases
   C. remains same
   D. none of the above

10. For which of the following applications a D.C. motor is preferred over an A.C. motor ?

    A. Low speed operation
    B. High speed operation
    C. Variable speed operation
    D. Fixed speed operation