A. Reduced current method
B. Tap changing control of transformer
C. Series parallel operation of motors
D. All of the above
Related Mcqs:
- 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 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 - 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 - 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 - Main traction systems used in India are, those using______________?
A. electric locomotives
B. diesel engine locomotives
C. steam engine locomotives
D. diesel electric locomotives
E. all of the above - An ideal traction system should have_______________?
A. easy speed control
B. high starting tractive effort
C. equipment capable of with standing large temporary loads
D. all of the above - ________________ frequency is not common in low frequency traction system?
A. 40 Hz
B. 25 Hz
C. 16 Hz
D. non of these - Which of the following is the voltage for single phase A.C. system ?
A. 22 V
B. 440 V
C. 5 kV
D. 15 kV
E. None of the above - For three-phase induction motors which of the following is the least efficient method of speed control ?
A. Cascade control
B. Pole changing
C. Rheostat control
D. Combination of cascade and pole changing - For 25 kV single phase system power supply frequency is_______________?
A. 60 Hz
B. 50 Hz
C. 25 Hz
D. 16 Hz
