Related Mcqs:

1. 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

2. 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

3. 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

4. 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

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

6. Which D.C. motor is preferred for elevators ?

   A. Shunt motor
   B. Series motor
   C. Differential compound motor
   D. Cumulative compound motor

7. Which of the following motor is preferred for operation in highly explosive atmosphere ?

   A. Series motor
   B. Shunt motor
   C. Air motor
   D. Battery operated motor

8. Which D.C. motor is generally preferred for cranes and hoists ?

   A. Series motor
   B. Shunt motor
   C. Cumulatively compounded motor
   D. Differentially compounded motor

9. In case-the conditions for maximum power for a D.C. motor are established, the efficiency of the motor will be______________?

   A. 100%
   B. around 90%
   C. anywhere between 75% and 90%
   D. less than 50%

10. In a D.C. series motor, if the armature current is reduced by 50%, the torque of the motor will be equal to

    A. 100% of the previous value
    B. 50% of the previous value
    C. 25% of the previous value
    D. 10% of the previous value
    E. none of the above