Essential Electric Traction Objective Questions
1.The efficiency of diesel locomotives is nearly
20 to 25 percent
30 to 40 percent
45 to 55 percent
60 to 70 percent
ANSWER : : 20 to 25 percent
2.Which of the following is the voltage for single phase A.C. system ?
22 V
440 V
5 kV
15 kV
ANSWER : : 22 V
3.For diesel locomotives the range of horsepower is
50 to 200
500 to 1000
1500 to 2500
3000 to 5000
ANSWER : : 1500 to 2500
4.Which of the following braking systems on the locomotives is costly ?
Regenerative braking on electric locomotives
Vacuum braking on diesel locomo-tives
Vacuum braking on steam locomo-tives
All braking systems are equally costly
ANSWER : : Regenerative braking on electric locomotives
5.Automatic signalling is used for which of the following trains ?
Mail and express trains
Superfast trains
Suburban and Urban electric trains
All trains
ANSWER : : Superfast trains
6.The speed of a superfast train is
60 kmph
75 kmph
100 kmph
more than 100 kmph
ANSWER : : more than 100 kmph
7.In case of locomotives the tractive power is provided by
single cylinder double acting steam engine
double cylinder, single acting steam engine
double cylinder, double acting steam engine
single stage steam turbine
ANSWER : : double cylinder, double acting steam engine
8.Which of the following drives is suitable for mines where explosive gas exists ?
Steam engine
Diesel engine
Battery locomotive
Any of the above
ANSWER : : Battery locomotive
9.Which of the following is the advantage of electric braking ?
It avoids wear of track
Motor continues to remain loaded during braking
It is instantaneous
More heat is generated during braking
ANSWER : : It avoids wear of track
10.In case of steam engines the steam pressure is
1 to 4 kgf/cm2
5 to 8 kgf/cm2
10 to 15 kgf/cm2
25 to 35 kgf/cm2
ANSWER : : 10 to 15 kgf/cm2
11.The number of passanger coaches that can be attached to a diesel engine locomotive on broad gauge is usually restricted to
5
10
14
17
ANSWER : : 10
12.Main traction systems used in India are, those using
electric locomotives
diesel engine locomotives
steam engine locomotives
diesel electric locomotives
ANSWER : s: e
13.The speed of a locomotive is controlled by
flywheel
gear box
applying brakes 11.
regulating steam flow to engine
ANSWER : : gear box
14.The wheels of a train, engine as well as bogies, are slightly tapered to
reduce frietion
increase friction
facilitate braking
facilitate in taking turns
ANSWER : : facilitate in taking turns
15.The overall efficiency of steam locomo�tive is around
5 to 10 percent
15 to 20 percent
25 to 35 percent
35 to 45 percent
ANSWER : : 5 to 10 percent
16.Which of the following state capitals is not on broad gauge track ?
Lucknow
Bhopal
Jaipur
Chandigarh
ANSWER : : Jaipur
17.Electric locomotives in India are manufactured at
Jamalpur
Bangalore
Chittranjan
Gorakhpur
ANSWER : : Chittranjan
18.Long distance railways use which of the following ?
200 V D.C.
25 kV single phase A.C. 10.
25 kV two phase A.C.
25 kV three phase A.C.
ANSWER : : 25 kV single phase A.C. 10.
19.Overload capacity of diesel engines is usually restricted to
2 percent
10 percent
20 percent
40 percent
ANSWER : : 2 percent
20._______ locomotive has the highest operational availability.
Electric
Diesel
Steam
Electric
ANSWER : he horsepower of steam locomotives is
21.. The steam engine provided on steam locomotives is
single acting condensing type
single acting non-condensing type
double acting condensing type
double acting non-condensing type
ANSWER : : single acting non-condensing type
22.In a steam locomotive electric power is provided through
overhead wire
battery system
small turbo-generator
diesel engine generator
ANSWER : : small turbo-generator
23.In tramways which of the following motors is used ?
D.C. shunt motor
D.C. series motor
A.C. three phase motor
AC. single phase capacitor start motor
ANSWER : : D.C. series motor
24.The value of co-efficient of adhesion will be high when rails are
greased
wet
sprayed with oil
cleaned with sand
ANSWER : : cleaned with sand
25.Series motor is not suited for traction duty due to which of the following account ?
Less current drain on the heavy load torque
Current surges after temporary switching off supply
Self relieving property
Commutating property at heavy load
ANSWER : : Current surges after temporary switching off supply
26.The specific energy consumption of a train depends on which of the following ?
Acceleration and retardation
Gradient
Distance covered
All of the above
ANSWER : : All of the above
27.Due to which of the following co-efficient of adhesion improves ?
Rust on the rails
Dust on the rails
Sand on the rails
All of the above
ANSWER : : All of the above
28.In main line service as compared to urban and suburban service
distance between the stops is more
maximum speed reached is high
acceleration and retardation rates are low
all of the above
ANSWER : : all of the above
29.Specific energy consumption becomes
more on steeper gradient
more with high train resistance
less if distance between stops is more
all of the above
ANSWER : : all of the above
30.Speed-time curve of main line service differs from those of urban and suburban services on following account
it has longer free running period
it has longer coasting period
accelerating and braking periods are comparatively smaller
all of the above
ANSWER : : all of the above
31.The friction at the track is proportional to
1/speed
l/(speed)2
speed
none of the above
ANSWER : : speed
32.For three-phase induction motors which of the following is the least efficient method of speed control ?
Cascade control
Pole changing
Rheostatic control
Combination of cascade and pole changing
ANSWER : : Rheostatic control
33.The pulsating torque exerted by steam locomotives causes which of the following?
Jolting and skidding
Hammer blow
Pitching
All of the above
ANSWER : : Jolting and skidding
34.The normal value of adhesion friction is
0.12
0.25
0.40
0.75
ANSWER : : 0.25
35.For given maximum axle load tractive efforts of AC. locomotive will be
less than that of D.C. locomotive
more than that of D.C. locomotive
equal to that of D.C. locomotive
none of the above
ANSWER : : more than that of D.C. locomotive
36.Battery operated trucks are used in
steel mills
power stations
narrow gauge traction
factories for material transportation
ANSWER : : factories for material transportation
37.Which of the following braking systems is used on steam locomotives ?
Hydraulic system
Pneumatic system
Vacuum system
None of the above
ANSWER : : Vacuum system
38.Co-efficient of adhesion is
high in case of D.C. traction than in the case of AC. traction
low in case of D.C. traction than in the case of AC. traction
equal in both AC. and D.C. traction
any of the above
ANSWER : : low in case of D.C. traction than in the case of AC. traction
39.Which of the following is the disadvantage of electric traction over other systems of traction ?
Corrosion problems in the under-ground pipe work
Short time power failure interrupts traffic for hours
High capital outlay in fixed instal-lations beside route limitation
Interference with communication lines
ANSWER : 3 All of the above
40.The resistance encountered by a trainin motion is on account of
resistance offered by air
friction at the track
friction at various parts of the rolling stock
all of the above
ANSWER : : all of the above
41.The rate of acceleration on suburban orurban services is restricted by the consideration of
Engine power
Track curves
Passenger Discomfort
Track size
ANSWER : : Passenger Discomfort
42.Quadrilateral speed-time curve pertains to which of the following services ?
Main line service
Urban service
Sub-urban service
Urban and sub-urban service
ANSWER : : Urban and sub-urban service
43.Locomotive having monomotor bogies
has better coefficient of adhesion
are suited both for passanger as well as freight service
has better riding qualities due to the reduction of lateral forces
has all above qualities
ANSWER : s: d
44.The voltage used for suburban trains in D.C. system is usually
12 V
24 V
220 V
600 to 750 V
ANSWER : : 600 to 750 V
45.Co-efficient of adhesion reduces due to the presence of which of the following ?
Sand on rails
Dew on rails
Oil on the rails
both (b) and (c)
ANSWER : : both (b) and (c)
23.The air resistance to the movement of the train is proportional to
speed
(speed)
(speed)
1/speed
ANSWER : : (speed)
24.Vacuum is created by which of the following?
Vacuum pump
Ejector
Any of the above
None of the above
ANSWER : : Any of the above
25.Which of the following methods is used to control speed of 25 kV, 50 Hz single phase traction ?
Reduced current method
Tap changing control of transformer
Series parallel operation of motors
All of the above
ANSWER : : Tap changing control of transformer
26.Which of the following happens in Kando system ?
Three phase A.C. is converted into D.C.
Single phase A.C. is converted into D.C.
Single phase supply is converted into three phase system
None of the above
ANSWER : : Single phase supply is converted into three phase system
27.For 25 kV single phase system power supply frequency is
60 Hz
50 Hz
25 Hz
16 Hz
ANSWER : : 50 Hz
28.Suri transmission is
electrical-pneumatic
mechanical-electrical
hydro-mechanical
hydro-pneumatic
ANSWER : : hydro-mechanical
29.Energy consumption in propelling the train is required for which of the following?
Work against the resistance to motion
Work against gravity while moving up the gradient
Acceleration
All of the above
ANSWER : : All of the above
30.Power for lighting in passanger coach, in a long distance electric train, is provided
directly through overhead electric line
through individual generator of bogie and batteries
through rails
through locomotive
ANSWER : : through individual generator of bogie and batteries
31.The return circuit for tramcars is through
neutral wire
rails
cables
common earthing
ANSWER : : rails
32.The rate of acceleration on suburban orurban service is in the range
0.2 to 0.5 km phps
1.6 to 4.0 km phps
5 to 10 km phps
15 to 25 km phps
ANSWER : : 1.6 to 4.0 km phps
33.In case of ________ free running and coasting periods are generally long.
main-line service
urban service
sub-urban service
all of the above
ANSWER : : main-line service
34.The braking retardation is usually in the range
0.15 to 0.30 km phps
0.30 to 0.6 km phps
0.6 to 2.4 km phps
3 to 5 km phps
ANSWER : : 3 to 5 km phps
35.If the co-efficient of adhesion on dry rails is 0.26, which of the following could be the value for wet rails ?
0.3
0.26
0.225
0.16
ANSWER : : 0.16
36.Specific energy consumption is affected by which of the following factors ?
Retardation and acceleration values
Gradient
Distance between stops
All of the above
ANSWER : : All of the above
37.For which of the following locomotives the maintenance requirements are the least?
Steam locomotives
Diesel locomotives
Electric locomotives
Equal in all of the above
ANSWER : : Diesel locomotives
38.An ideal traction system should have
easy speed control
high starting tractive effort
equipment capable of with standing large temporary loads
all of the above
ANSWER : : all of the above
39.Overhead lines for power supply to tramcars are at a minimum height of
3 m
6 m
10 m
tO m
ANSWER : : 10 m
40.In India, electrification of railway track was done for the first time in which of the following years ?
1820�1825
1880�1885
1925�1932
1947�1954
ANSWER : : 1925�1932
41.Specific energy consumption is least in _______ service.
main line
urban
suburban
main line
ANSWER : Locomotives with monometer bogies have
42.The coasting retardation is around
0.16 km phps
1.6 km phps
16 km phps
40 km phps
ANSWER : : 0.16 km phps
43.In case of a steam engine an average coal consumption per km is nearly
150 to 175 kg
100 to 120 kg
60 to 80 kg
28 to 30 kg
ANSWER : : 28 to 30 kg