# Utilization of electrical System 5

Electrical Engineering MCQ Question Papers: Campus Placement

Subject: Utilization of electrical System 5

Part 5: List for questions and answers of Utilization of Electrical System

Q1. The magnitude for the tractive effort which is required for the propulsion of the train depends on

b) Friction between the driving wheel and the track

c) Both (a) and (b)

d) Neither (a) nor (b)

Q2. If W is the dead weight of the train in tones and A is the acceleration of the train in kmphps then the tractive effort required for linear acceleration is given by

a) WA newtons

b) 177.7 WA newtons

c) 277.8 WA newtons

d) 388.8 WA newtons

Q3. During the train movement, the tractive effort produced at the pinion by the motor is transferred to the driving wheel

a) Directly

b) Through the gear wheel

d) Through the motor armature

Q4. The area under the speed – time curve represents the

a) Acceleration of the train

b) Time taken by the train

c) Distance travelled by the train

d) Crest speed

Q5. The scheduled speed of a train can be increased by

a) Increasing the acceleration and retardation

b) Increasing the crest speed

c) Decreasing the duration of stop

d) All of these

Q6. The ratio of the distance between any two stops and the sum of the time of run and the time of stop at one station is known as

a) Crest speed

b) Average speed

c) Maximum speed

d) Scheduled speed

Q7. In mail line train services, the

a) Acceleration and braking periods are long

b) Acceleration and braking periods are short

c) Free run and coasting periods are long

d) Both (b) and (c)

Q8. In urban or city train service, the

a) Acceleration period is absent

b) Free running period is absent

c) Coasting period is absent

d) Braking period is absent

Q9. In speed time curve for trains, the notching period is

a) Constant acceleration period

b) Free running period of the train

c) Braking period of the train

d) Coasting period of the train

Q10. The slope of the speed – time curve at any point gives the

a) Acceleration of the train at that point of time

b) Retardation of the train at that point of time

c) Distance travelled by the train

d) Either (a) or (b)

Q11. Braking retardation on suburban trains is

a) 0.3 to 0.5 km phps

b) 0.5 to 1 km phps

c) 3 to 5 km phps

d) 30 to 40 km phps

Q12. Power supply frequency for 25 kV single phase system is

a) 161

b) 25

c) 50

d) 60

Q13. For supply on 25 kV, 50 Hz single phase, suitable motor for electric traction is

a) Ac single phase split phase motor

b) Ac single phase universal motor

c) Dc shunt motor

d) Dc series motor

Q14. Method of speed control used on 25 kV, 50 Hz single phase traction is

a) Tap changing control of transformer

b) Reduced current method

c) Series parallel operation of motors

d) Any of the above

Q15. The coefficient of adhesion is highest when

a) The rails are dry

b) The rails are oiled

c) The rails ark wet with dew

d) The rails are dusty

Q16. When the speed of the train is estimated taking into account the time of stop at a station in addition to the actual running time between stops, is known as

a) Average speed

b) Schedule speed

c) Notching speed

d) Free running speed

Q17. A schedule speed of 45 km, per hour is required between two stops 1.5 km apart. The duration of stop is 20 seconds. The acceleration is 2.4 km phps and retardation is 3.2 km phps. For a simplified trapezoidal curve the maximum speed over the mil will be

a) 40 km per hour

b) 48 km per hour

c) 74 km per hour

d) 90 km per hour

Q18. Speed of locomotive is controlled by

a) Gear box

b) Flywheel

c) Regulating steam to engine

d) Applying brakes

Q19. The specific energy consumption for suburban services is usually

a) 18 to 25 watt-hours per tonne km

b) 50 to 75 watt-hours per tonne km

c) 125 to 150 watt-hours per tonne km

d) 155 to 200 watt-hours per tonne km

Q20. If the specific energy consumption for suburban services is 50 to 75 watts hours per tonne km, which of the following could be a representative figure for energy consumption on main line service

a) 150 to 200 watt-hours per tonne km

b) 100 to 125 watt-hours per tonne km

c) 50 to 75 watt-hours per tonne km

d) 20 to 30 watt-hours per tonne km

Part 5: List for questions and answers of Utilization of Electrical System