197. 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. Interference with communication lines
D. All of the above

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198. Co-efficient of adhesion is
A. high in case of D.C. traction than in the case of A.C. traction
B. low in case of D.C. traction than in the case of A.C. traction
C. equal in both A.C. and D.C. traction
D. any of the above

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199. Speed-time curve of main line service differs from those of urban and sub-urban services an following account
A. it has longer free running period
B. it has longercoasting period
C. accelerating and braking periods are comparatively smaller
D. all of the above

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200. The rate of acceleration on suburban or urban services is restricted by the consideration of
A. engine power
B. track curves
C. passanger discomfort
D. track size

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201. The specific energy consumption of a train depends on which of the following
A. Acceleration and retardation
B. Gradient Distance covered
C. All of the above
D. None of these

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202. The friction at the track is proportional to
A. 1/speed
B. 1/(speed)2
C. speed
D. none of the above

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203. The air resistance to the movement of the train is proportional to
A. speed
B. (speed)2
C. (speed)3
D. I /speed

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