Top 250+ Solved Control of Electric Drives MCQ Questions Answer
Q. Tractive effort is required to
a. overcome the gravity component of train mass
b. overcome friction, windage and curve resistance
c. accelerate the train mass
d. do all of the above
Q. For given maximum axle load tractive efforts of AC. locomotive will be
a. less than that of D.C. locomotive
b. more than that of D.C. locomotive
c. equal to that of
d. C. locomotive
Q. Due to which of the following co-efficient of adhesion improves ?
a. Rust on the rails
b. Dust on the rails
c. Sand on the rails
d. All of the above
Q. Which of the following is the disadvantage of electric traction over other systems oftraction ?
a. Corrosion problems in the under-ground pipe work
b. Short time power failure interrupts traffic for hours
c. High capital outlay in fixed instal-lations beside route limitation
d. Interference with communication lines
Q. Speed-time curve of main line service differs from those of urban and suburbanservices on following account
a. it has longer free running period
b. it has longer coasting period
c. accelerating and braking periods are comparatively smaller
d. all of the above
Q. The rate of acceleration on suburban orurban services is restricted by theconsideration of
a. Engine power
b. Track curves
c. Passenger Discomfort
d. Track size
Q. The specific energy consumption of a train depends on which of the following ?
a. Acceleration and retardation
b. Gradient
c. Distance covered
d. All of the above
Q. The friction at the track is proportional to
a. 1/speed
b. l/(speed)2
c. speed
d. none of the above
Q. The resistance encountered by a train in motion is on account of
a. resistance offered by air
b. friction at the track
c. friction at various parts of the rolling stock
d. all of the above
Q. Battery operated trucks are used in
a. steel mills
b. power stations
c. narrow gauge traction
d. factories for material transportation
Q. method can bring the locomotive to dead stop.
a. Plugging braking
b. Rheostatic braking
c. Regenerative braking
d. None of the above
Q. The voltage used for suburban trains in D.C. system is usually
a. 12 V
b. 24 V
c. 220 V
d. 600 to 750 V
Q. For three-phase induction motors which of the following is the least efficient method of speed control ?
a. Cascade control
b. Pole changing
c. Rheostatic control
d. Combination of cascade and pole changing
Q. Specific energy consumption becomes
a. more on steeper gradient
b. more with high train resistance
c. less if distance between stops is more
d. all of the above
Q. In main line service as compared to urban and suburban service
a. distance between the stops is more
b. maximum speed reached is high
c. acceleration and retardation rates are low
d. all of the above