Which of the following motors is preferred for traction work ?

Related Mcqs:

1. Which of the following is an advantage of electric traction over other methods of traction ?

   A. Faster acceleration
   B. No pollution problems
   C. Better braking action
   D. All of the above

2. Which of the following is the disadvantage of electric traction over other systems of traction ?

   A. Corrosion problems in the under-ground pipe work
   B. Short time power failure interrupts traffic for hours
   C. High capital outlay in fixed installations beside route limitation
   D. Interference with communication lines
   C. All of the above

3. For which of the following applications D.C. motors are still preferred ?

   A. High efficiency operation
   B. Reversibility
   C. Variable speed drive
   D. High starting torque

4. Which of the following motors is usually preferred for kiln drives ?

   A. Cascade controlled A.C. motor
   B. Slip ring induction motor
   C. Three phase shunt wound com-mutator motor
   D. Any of the above

5. For a motor-generator set which of the following motors will be preferred ?

   A. Synchronous motor
   B. Slip ring induction motor
   C. Pole changing induction motor
   D. Squirrel cage induction motor

6. Which of the following motors is preferred when quick speed reversal is the main consideration ?

   A. Squirrel cage induction motor
   B. Wound rotor induction motor
   E. Synchronous motor
   D. D.C. motor

7. Which of the following motors is preferred for boom hoist of a travelling crane ?

   A. Single phase motor
   B. Synchronous motor
   C. A.C. slip ring motor
   D. Ward-Leonard controlled D.C. shunt motor

8. Which of the following motors is preferred when smooth and precise speed control over a wide range is desired ?

   A. D.C. motor
   B. Squirrel cage induction motor
   C. Wound rotor induction motor
   D. Synchronous motor

9. Series motor is not suited for traction duty due to which of the following account ?

   A. Less current drain on the heavy load torque
   B. Current surges after temporary switching off supply
   C. Self relieving property
   D. Commutating property at heavy load

10. Which of the following methods is used to control speed of 25 kV, 50 Hz single phase traction ?

    A. Reduced current method
    B. Tap changing control of transformer
    C. Series parallel operation of motors
    D. All of the above