1. Quadrilateral speed time curve is used for
- urban service
- main line service
- goods line service
- sub urban service
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.
- Regenerative brake
- Synchronous brake
- Generative brake
- Recursive brake
3. The coefficient of adhesion is highest when
- The rails are dusty
- The rails are wet
- The rails are dry
- The rails are oiled
4. Co-efficient of adhesion is
- high in case of D.C. traction than in case of A.C. traction
- low in case of D.C. traction than in case of A.C. traction
- equal in both A.C. and D.C. traction
- any of these
5. Specific energy consumption is least in
- Urban service
- Sub-urban service
- Main-Line service
- Equal for all type of services
6. The electric locomotive run faster at curved routes as compared to the steam locomotive as
- The centre of gravity of electric locomotive is higher than that of steam locomotive
- The centre of gravity of electric locomotive is lower than that of steam locomotive
- The speed at curved routes is independent of location of centre of gravity
- None of above
7. In traction mechanics the gear ratio (γ) is equal to
- (Specd of motor pinion in rpm)/(Speed of driving axle in rpm)
- (Speed of driving axle in rpm)/(Speed of driving axle in rpm)
- (Speed of driving axle in rpm)2/(Speed of motor pinion in rpm)2
- (Speed of driving axle in rpm) x (Speed of motor pinion in rpm)
8. Long-distance railways use for their electric traction
- 200 V DC
- 25 kV single-phase AC
- 25 kV two-phase DC
- 25 kV three-phase AC
9. In a steam locomotive, electric power is provided through
- Battery system
- Diesel engine generator
- Overhead wire
- Small turbo generator
10. For traction work, which motor is preferred?
- Synchronous motor
- Three-phase induction motor
- D.C. series motor
- Universal motor
11. The advantage of electric breaking is
- It is instantaneous
- More heat is generated during breaking
- It avoids wear of track
- Motor continues to remain loaded during breaking
12. Low-frequency operation of AC series motor in traction application
- Improve its commutation, pf and efficiency
- Adversely affects commutation but pf and efficiency improve.
- Improves its commutation but starting current increases.
- Improves its commutation property but pf and efficiency reduce.
13. The efficiency of diesel locomotive is
- 70% to 80%
- 20% to 30%
- 50% approximately
- 10% to 20%
14. Sub urban railway system in India use voltage
- 400 V, 3-phase A.C.
- 660V, 3-phase A.C.
- 1500 V, D.C.
- 3.3 KV, 3-phase A.C.
15. Electric traction in comparison to other traction Systems has the advantages of
- Higher acceleration and breaking retardation
- Cleanest system and so ideally suitable for the underground and tube railways
- Better speed control
- All of these
16. Electric railway in comparison to other traction has the drawbacks of
- interface with communication lines running along the track
- heavy initial expenditure in laying out overhead electric supply system
- interruption of traffic for hours owing to short-time power failure
- all option are correct
17. Diesel-electric traction has comparatively limited overload capacity because
- Diesel engine is constant output prime mover
- Diesel engine has shorter life span
- Regenerative braking cannot be employed
- Diesel-electric locomotive is heavier than an ordinary electric locomotive
18. An ideal traction system should have
- high starting tractive effort.
- equipment capable of withstanding large temporary overloads.
- easy speed control.
- All options are correct
19. If the designation of Indian Railways locomotive is known as WAM1, then in this the letter W indicates which of the following?
- The locomotive is to run on broad gauge
- The locomotive is to run on metre gauge
- The locomotive is for shunting duty
- The locomotive is for goods train only
20. Why is electric braking preferred?
- It is smooth
- Its maintenance cost is less
- The energy is saved in regenerating braking
- All options are correct