Why are the D.C. motors preferred for traction applications?

A Torque and speed are inversely proportional to armature current
B Torque is proportional to armature current
C Torque is proportional to square root of armature current
D The speed is inversely proportional to the torque and the torque is proportional to square of armature current

Correct Answer: The speed is inversely proportional to the torque and the torque is proportional to square of armature current

Bissoy MCQ
#Electrical Engineering #D.C. Motors

Related Questions

Which of the following motors is preferred for traction work?
A Universal motor
B D.C. series motor
C Synchronous motor
D Three-phase induction motor
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
Which of the following is the disadvantage of electric traction over other systems of traction?
A Corrosion problems in the underground 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
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
Which one of the following is not necessarily the advantage of D.C. motors over A.C. motors?
A Low cost
B Wide speed range
C Stability
D High starting torque
Which of the following motors is preferred for tape-recorders?
A Shaded pole motor
B Hysteresis motor
C Two value capacitor motor
D Universal motor
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
C Synchronous motor
D D.C. motor
Which of the following motors are preferred for overhead traveling cranes?
A Slow speed motors
B Continuous duty motors
C Short time rated motors
D None of the above
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
Short time rated motors are preferred for overhead traveling cranes
A True
B False

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