Electric Traction MCQ

1. Quadrilateral speed time curve is used for

  1. urban service
  2. main line service
  3. goods line service
  4. sub urban service
Answer
Answer. a

2. A ________ is an energy recovery mechanism which slows a vehicle or object by converting its kinetic energy into a form which can be either used immediately or stored until needed.

  1. Regenerative brake
  2. Synchronous brake
  3. Generative brake
  4. Recursive brake
Answer
Answer. a

3. The coefficient of adhesion is highest when

  1. The rails are dusty
  2. The rails are wet
  3. The rails are dry
  4. The rails are oiled
Answer
Answer. c

4. Co-efficient of adhesion is

  1. high in case of D.C. traction than in case of A.C. traction
  2. low in case of D.C. traction than in case of A.C. traction
  3. equal in both A.C. and D.C. traction
  4. any of these
Answer
Answer. b

5. Specific energy consumption is least in

  1. Urban service
  2. Sub-urban service
  3. Main-Line service
  4. Equal for all type of services
Answer
Answer. c

6. The electric locomotive run faster at curved routes as compared to the steam locomotive as

  1. The centre of gravity of electric locomotive is higher than that of steam locomotive
  2. The centre of gravity of electric locomotive is lower than that of steam locomotive
  3. The speed at curved routes is independent of location of centre of gravity
  4. None of above
Answer
Answer. b

7. In traction mechanics the gear ratio (γ) is equal to

  1. (Specd of motor pinion in rpm)/(Speed of driving axle in rpm)
  2. (Speed of driving axle in rpm)/(Speed of driving axle in rpm)
  3. (Speed of driving axle in rpm)2/(Speed of motor pinion in rpm)2
  4. (Speed of driving axle in rpm) x (Speed of motor pinion in rpm)
Answer
Answer. a

8. Long-distance railways use for their electric traction

  1. 200 V DC
  2. 25 kV single-phase AC
  3. 25 kV two-phase DC
  4. 25 kV three-phase AC
Answer
Answer. b

9. In a steam locomotive, electric power is provided through

  1. Battery system
  2. Diesel engine generator
  3. Overhead wire
  4. Small turbo generator
Answer
Answer. d

10. For traction work, which motor is preferred?

  1. Synchronous motor
  2. Three-phase induction motor
  3. D.C. series motor
  4. Universal motor
Answer
Answer. c

11. The advantage of electric breaking is

  1. It is instantaneous
  2. More heat is generated during breaking
  3. It avoids wear of track
  4. Motor continues to remain loaded during breaking
Answer
Answer. d

12. Low-frequency operation of AC series motor in traction application

  1. Improve its commutation, pf and efficiency
  2. Adversely affects commutation but pf and efficiency improve.
  3. Improves its commutation but starting current increases.
  4. Improves its commutation property but pf and efficiency reduce.
Answer
Answer. a

13. The efficiency of diesel locomotive is

  1. 70% to 80%
  2. 20% to 30%
  3. 50% approximately
  4. 10% to 20%
Answer
Answer. b

14. Sub urban railway system in India use voltage

  1. 400 V, 3-phase A.C.
  2. 660V, 3-phase A.C.
  3. 1500 V, D.C.
  4. 3.3 KV, 3-phase A.C.
Answer
Answer. c

15. Electric traction in comparison to other traction Systems has the advantages of

  1. Higher acceleration and breaking retardation
  2. Cleanest system and so ideally suitable for the underground and tube railways
  3. Better speed control
  4. All of these
Answer
Answer. d

16. Electric railway in comparison to other traction has the drawbacks of

  1. interface with communication lines running along the track
  2. heavy initial expenditure in laying out overhead electric supply system
  3. interruption of traffic for hours owing to short-time power failure
  4. all option are correct
Answer
Answer. d

17. Diesel-electric traction has comparatively limited overload capacity because

  1. Diesel engine is constant output prime mover
  2. Diesel engine has shorter life span
  3. Regenerative braking cannot be employed
  4. Diesel-electric locomotive is heavier than an ordinary electric locomotive
Answer
Answer. a

18. An ideal traction system should have

  1. high starting tractive effort.
  2. equipment capable of withstanding large temporary overloads.
  3. easy speed control.
  4. All options are correct
Answer
Answer. d

19. If the designation of Indian Railways locomotive is known as WAM1, then in this the letter W indicates which of the following?

  1. The locomotive is to run on broad gauge
  2. The locomotive is to run on metre gauge
  3. The locomotive is for shunting duty
  4. The locomotive is for goods train only
Answer
Answer. a

20. Why is electric braking preferred?

  1. It is smooth
  2. Its maintenance cost is less
  3. The energy is saved in regenerating braking
  4. All options are correct
Answer
Answer. d
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