190. Which of the following is the advantage of electric braking?
A. It avoids wear of track
B. Motor continues to remain loaded during braking
C. It is instantaneous
D. More heat is generated during braking

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191. Which of the following braking systems on the locomotives is costly?
A. Regenerative braking on electric locomotives
B. Vacuum braking on diesel locomotives
C. Vacuum braking on steam locomotives
D. All braking systems are equally costly

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192. 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

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193. For given maximum axle load tractive efforts of A.C. 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
D. none of the above

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194. Co-efficient of adhesion reduces due to the presence of which of the following?
A. Sand on rails
B. Dew on rails
C. Oil on the rails
D. both and

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195. 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

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196. Quadrilateral speed-time curve pertains to which of the following services?
A. Main line service
B. Urban service
C. Sub-urban service
D. Urban and sub-urban service

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