Previous Exams

Electrician(Water Transport) - 2016

 

Time Remaining :
1. Which of the following frequencies has the longest time period?
1Hz
1 kHz
10 Hz
10 kHz
2. In a generator maximum value of e.m.f.is generated within the coil axis is at:
45 degree with field axis
90 degree with field axis
180 degree with field axis
Zero degree with field axis
3. A choke coil of an operating fluorescent lamp is short-circuited.What is the consequence?
The lamp becomes brighter
The lamp becomes less bright
The current becomes so large that it damages the tube
The short circuit is noticed only after the lamp is switched ‘ON’again
4. A contactor coil is designed for 220V DC.What happens if it is connected to 220 V AC?
Too large a current is drawn by the coil and it is destroyed
Too small a current is drawn by the coil and the operation the contator is no longer certain
It draws the same current
It works better
5. A capacitor is connected across a 200 V AC line.Its minimum voltage rating should be:
100 volt
200 volt
300 volt
400 volt
6. The power factor of 3-phase load is less than 0.5.While measuring power by two watt meters:
One of the wattmeters gives zero reading
One of the wattmeters gives negative reading
Both wattmeters give positive reading
One of the wattmeters kicks backward
7. Voltage required to operate the Neon sign tubes depends upon:
Diameter of the tube
Gases in the tube
Length of the tube
Thickness of the tube
8. Soldering of a Britania Joint is a necessity to avoid loosening of the joint due to:
Vibration and change in atmospheric temperature
Corrosion due to galvanic action
Corrosion due to atmospheric changes
Overheating
9. The testing of wiring installation for insulation resistance to ensure that:
All conductors have high ohmic values in the circuit
All outlet points are earthed properly to ground
Leakage current beyond the stipulated value does not flow to earth
Live and neutral conductors in the installation are continuous
10. Braking torque in energy meter is produced to:
Brake the instrument
Bring energy meter to stand still
Safeguard it against creep
Maintain steady speed and equal to driving torque
11. The scale of dynamometer type wattmeter is of:
Uniform scale
Logarithmic scale
Non-linear scale
Square law scale
12. The standard secondary voltage for PT used in power system in:
1 V
5 V
50V
110 V
13. Which instrument always indicates true r.m.s.value irrespective of the waveform?
Moving iron meter
Digital voltmeter
Thermocouple meter
None of the above
14. A voltmeter gives inaccurate reading to measure the drop across a low resistance because:
The higher scale has been selected
The current drawn by the meter is too low
The sensitivity of the meter is too low
None of the above
15. The phase difference between the currents in the two pressure coils in PF meter is:
Approximately 0 degree
Approximately 90 degree
Exactly 0 degree
Exactly 90 degree
16. When a rewound armature is rolled on the surface of a leveled surface plate the armature stops at the same position of its periphery for each rolling,the portion of armature touching the surface plat
Higher weight than the diametrically opposite portion
Lesser weight than the diametrically opposite portion
Equal weight to that of opposite portion
Higher weight than the portion 90 degree to it on any one side
17. Which one of the following characteristic is NOT applicable to synchronous motors?
Runs at constant speed at all loads
Suitable to supply only mechanical load
Can also be used for PF improvement
Not self starting
18. Which method is generally adopted to measure the power in a three phase imbalanced load system?
One wattmeter method
Two wattmeter method
Three voltmeter method
Three wattmeter method
19. The colour of light depends upon:
Wave length
Frequency
Speed of light
Frequency and wave length
20. Which of the following lamp is a cold cathode lamp?
Neon lamp
Sodium vapour lamp
Mercury vapour lamp
Fluorescent lamp
21. You have to repair storage type water heater which has steam in the hot water.The possible remedy for this trouble can be found by checking:
All points for possible leakages
The thermostat setting
All wiring for loose connections
Element for its condition
22. The reading on a 3 digit millivoltmeter started flashing continuously when connected across a resistor to measure the m V across it.The reason for flashing of display on millivoltmeter is that:
The battery in the instrument is weak
There is no battery in the instrument
The measured value is over range
The display is damaged
23. Which one of the following measurement CANNOT be done with multimeter?
Current drawn by an electronic circuit
Supply voltage to DC motor
Continuity test of motor winding
Insulation resistance of motor
24. Why a higher capacity squirrel cage induction motor is not recommended for operating under low load condition?
Voltage drop in line will be too much
Power factor will be less
Higher capacity motors does not run at constant speed
Torque is too much hence it may cause damage
25. Shunts and multipliers used in MC instruments are made up of Mangnin.The reason for using the above metal is that,it has:
Positive temperature Co-efficient of resistance
Negative temperature Co-efficient of resistance
Perfectly constant temperature co-efficient of resistance
Very low(Practically const-ant)temperature co-efficient of resistance
26. In order to operate a fluorescent tubeset on DC supply,which of the following additional auxillary device is to be connected?
Inductance
Capacitance
Resistance
No extra device is needed
27. The power input increases by three times when the connection of three phase loads changes from star to delta at the same line voltage.What is the reason for this?
The voltage across one phase of the load is three times higher in delta connection than in star connection
The power factor increases by three times in delta connection when compared to star connection
The line current is three times higher in delta connection than in star connection
The voltage in each phase increases by two times and the current by 1.732 times
28. In a parallel resonant circuit the capacitor current is:
More than line current
Less than line current
Equal to line current
None of the above
29. According to National electric code what is the specified minimum distance between the washing unit and the switch board:
0.6 metre
2.5 metre
1.3 metre
3.4 metre
30. A series RLC circuit takes leading power factor current at:
Resonant frequency
More than resonant frequency
Less than resonant frequency
None of the above
31. In the output voltage of a DC generator the ripple effects can be reduced by increasing the:
Field current
Number of armature coil
Number of turns in the field winding
Size of the conductor of the armature coil
32. While installing power sub-circuits in domestic installations it should be restricted to:
800 watts with in 10 light and fan points
800 watts within 2 outlets
3000 watts within 10 light and fan points
3000 watts within 2 outlets
33. What type of compounding would be desirable in the DC generator feeding a long transmission line?
Over compounding
Under compounding
Flat compounding
Any one of the above
34. The most economic method of electrical braking is:
Plugging
Dynamic braking with self excitation
Regenerative braking
Dynamic braking with separate excitation
35. When a DQ series motor is connected to an AC supply,then:
It will stop
It may burnt out
It will run without any trouble
It will run with less efficiency and high spark at commutator
36. Dummy coils in a DC generator is provided:
To ampily voltage
To reduce eddy current losses
To enhance flux density
To provide mechanical balance to the rotor
37. When the number of poles and the number of armature conductors are fixed,then which winding of a DC generator will give the higher e.m.f?
Wave winding
Lap winding
Same e.m.f.in lap wave winding
Depends on other features of design
38. Earth tester is used for measuring earth resistance in which generated DC is converted into AC by current reverser.The reason for using AC supply for resistance measurement is:
AC resistance is more than DC resistance
To reduce error due to electrolytic e.m.f
AC wave form is pulsating in nature
AC contains sine wave form
39. The basic function of voltage stabilizer is to provide:
Constant current supply to load
Constant power supply to load
Constant voltage supply to load
Uniterrupted supply to load
40. A food mixture rated for 240V AC fails to start when it is switched on.Which one of the following is NOT a cause for the above?
Jammed rotor
Supply voltage is only 210V
OL relay is not re-set
Open in armature winding
41. In a transformer the leakage flux may be minimized by:
Minimizing the number of turns of both the winding
Sectionalizing and inter-leaving the primary and secondary winding
Keeping the magnetizing current to the minimum
Reducing the reluctance of the iron core to the minimum
42. Which one of the following connections is preferred for three-to-two phase conversion?
Scott
Double scott
Star/star
Star/Double-delta
43. The phase relationship between primary and secondary terminal voltage of a transformer is:
Primary voltage is leading the secondary voltage by 90 degree
Secondary voltage is leading the primary voltage by 90 degree
180 degree out of phase
In the same phase
44. The no load primary current Io in an ideal transformer is:
In phase with VI
Leads VI by 90 degree
Lags behind VI by 90 degree
Lags VI by an angle lying between 0 degree and 90 degree
45. An optocoupler is a single package of:
LED and a signal diode
LED and a photodiode
Two photodiodes
Two LEDs
46. One of the diode of a bridge rectifier connected to 100 V 50Hz AC input is found to be damaged.The DC output of the circuit is 90V.The minimum value of PIV of the diode required for replacement is:
45 V
50 V
100 V
150 V
47. You are working with a fully automatic star delta starter.You notice that when start switch is pressed the motor starts in star but does not change to delta.The trouble will be in:
Delta contractor
Timer and its circuit
Star contractor
Line contractor
48. Watt-hour meter is classified as a:
Deflecting instrument
Indicating instrument
Recording instrument
Integrating instrument
49. Two pin sockets should not be used in domestic wiring unless the appliance to be connected is:
Double earth
Double insulated
Controlled by ELCB
Controlled by MCB
50. As load on induction motor increases its power factor:
Remain constant
Goes on decreasing
Goes on increasing over after full load
Goes on increasing up to full load and then it falls again
51. During no load test of a 3 phase induction motor,the motor draws power:
For core loss and copper loss
For copper loss and windage-friction loss
For core loss and windage-friction loss
Only for every small copper loss
52. The recent method of smooth speed control of a three-phase induction motor over a wide range is:
Frequency control method
Rotor resistance control method
Voltage control method
None of the above methods
53. Rotor bars of squirrel cage rotor are sometimes skewed:
To prevent rotor from aligning and locking up with stator
To give more uniform torque
To reduce humming noise
Due to all above reasons
54. For 66 kV lines the number of insulator discs used is:
3
6
10
12
55. AC resistance of a line conductor is more than its DC resitance because of:
Skin effect
Proximity effect
Skin effect and proximity effect
None of these
56. What type of insulator will be used if the direction of the transmission line is changed?
Strain type
Shackle type
Pin type
Suspension type
57. The back emf set up in the armature of a synchronous motor depends on:
Rotor speed only
Rotor excitation only
Rotor excitation and rotor speed
Coupling angle,rotor speed and excitation
58. The current drawn by an over excited synchronous motor will be:
Depending on the nature of load
At lagging power factor
At leading power factor
At unity power factor
59. Two alternators are sharing an inductive load equally.What will be happened if the excitation of one alternator is increased?
Another alternator will deliver more current
Another alternator will deliver less current
Both will continue to share load equally
Both will deliver more current
60. A ceiling fan rotates slowly in either direction.The probable fault is:
An open in centrifugal switch
An open in capacitor
Short in the capacitor
Blown fuse
61. In repulsion motor, maximum torque is developed when:
Brush axis is at 180 degree electrical to the field axis
Brush axis is at 90 degree electrical to the field axis
Brush axis is at 45degree electrical to the field axis
Brush axis coincides with the field axis
62. Starting winding of a single phase motor of a refrigerator is disconnected from the circuit by means of a:
Centrifugal switch
Magnetic relay
Thermal relay
None of the above
63. How the speed control of universal motor used for sewing machine is done?
Introducing friction mecca-nism
Tapping the field at various point
Centrifugal mechanism
Introducing a variable resistance in series with the motor
64. Buchholz relay is operated by:
Gas pressure
Eddy current
Electrostatic induction
Electromagnetic induction
65. The size of earth wire is determined by:
The atmospheric condition
The voltage of the service wires
The current capacity of the service wires
None of these
66. Earthing in consumer premises is necessary to give protection against:
Overloading
Danger of electric shock
Voltage fluctuation
High temperature of the conductors
67. A single phase protection switch is used to protect:
The distribution transformer
The motor in case of fuse failure
The motor from the damage due to single phasing
From the maximum starting current of motor
68. The best location of the power factor improving device to be installed the transmission line is at:
The receiving end
The sending end
Middle of the line
Any place
69. --------motor has series characteristics
Capacitor start motor
Shaded pole motor
Repulsion motor
None of the above
70. How the light output is produced in electric discharge lamp?
By heating effect of current
By magnetic effect of current
By ionization in a gas or vapour
By cathode ray emission
71. Arc heating occurs when the air between electrodes of opposite polarity becomes:
Moistened
Dry
Ionized
None of the above
72. The meter used to measure the temperature of a furnace is:
Hydrometer
Pyrometer
Hygrometer
Tachometer
73. Which part is provided in a battery charger to prevent the flow of excessive curret into the battery?
Coarse selector
Tune selector switch
Limiting resistance
Transformer
74. What will happen to the filter circuit in battery charger if the output filter capacitor is opened?
Will not function
Will make humming noise
More current will flow
No output voltage
75. What are the two relative quantities to be plotted for external characteristics curve for DC shunt generator?
Field current Vs No load voltage
Armature current Vs Induced e.m.f
Load current Vs Terminal voltage
Load current Vs Induced e.m.f
76. What will happen to a self excited DC generator,if the generator runs in reverse direction?
The induced e.m.f.is increased
There is no change in the induced e.m.f
Spark will be produced in the commutator
Residual magnetism in the pole will be destroyed
77. Which is the application of delayed response type diazed fuse?
Motor circuits
Heating circuits
Lighting circuits
Electronic circuits
78. The force between two long parallel conductors is inversely proportional to:
Current in one conductor
Distance between the conductors
Radius of conductors
Product of current in two conductors
79. Which of the following circuit elements will oppose the change in the circuit current?
Inductance
Resistance
Capacitance
All of the above
80. The colour of light of mercury vapour lamp is:
Greenish blue
Yellow
Pink
White
81. South Africa was captured by Britain after the -----------war.
Opium war
Boer war
Boxer Rebellion
Carnatic war
82. The King of England during the American war of independence:
George IIIrd
George 1st
Henry VIII
Charles 1st
83. The classical dance form popular in the North-East parts of India:
Bihu
Chiraw
Manipuri
Kathak
84. The author of the famous book”Fidelio”:
T.S.Eliot
L.Beethoven
Lord Byron
George Bernard Shaw
85. The Headquarters of Economic and Social Commission for Asia and the Pacific(ESCAP)is at:
Jakarta
Manila
Kathmandu
Bangkok
86. Language in which maximum number of Newspapers are published?
Marathi
English
Hindi
Bengali
87. French official book:
Yellow book
White book
Green book
Blue book
88. The author of “Truth,Love and a Little Malice”:
Boris Pasternak
U.Thant
Amita Malik
Khushwant Singh
89. Who was the founder of Scientific Astronomy?
Hippalus
Hoffmann
Hippocrates
None of these
90. Who propounded the signs of the Zodiac?
Indians
Egyptians
Babylonians
None of these
91. A social Reformer of Kerala who started Atmavidhya Sangham was:
Vaikunda Swamikal
Brahmananda Sivayogi
Thycaud AyyaVaikunda
Vagbhadanandan
92. ”The Career and legend of Vasco da Gama”is a book written by:
Sanjay Subramaniyam
Arun Shourie
Kushwant Singh
None of these
93. Who among the foreign travellers made earliest reference regarding Kerala?
Marco Polo
Megasthanese
Ptolemy
Pliny
94. The Newspaper “Sujananadini”was started by:
C.V.Kunhiraman
C.Krishnan
Kesavan Asan
Sahodaran Ayyapan
95. Under 42nd amendment to our constitution the fundamental duties were enumerated.This concept of fundamental duties was borrowed from the constitution of:
USSR
Ireland
China
UK
96. The Rajya Sabha is a ------------body.
A part of the Lok Sabha
A temporary body
A permanent body
None of these
97. Article 368 deals with:
Special Provision for Jammu and Kashmir
President rule in a state
Pertains to the abolition of untouch ability
Amendment of the Constitution
98. ”Neel Darpan”is a play which portrays the oppression meted out by the indigo planters over the peasants.This famous Play was written by whom?
Raja Ram Mohan Roy
Dinbandhu Mitra
Jyothirao Phule
R.N.Tagore
99. Which of the following is one of the Harappan sites related to the maritime activities of the Harappan people?
Lothal
Kalibangan
Rangpur
Mohanjodaro
100. The cold current which meets with the warm gulf stream near Newfoundland?
Humboldt
Canaries
Benguala
Labrador