PROVISIONAL ANSWER KEY
Question Code: 046/2024
Medium of Question- English
Name of Post: Electrician, Overseer Gr II/ Draftsman Gr II (Electrical), Electrician Police Constable, Skilled Assistant Gr II, Tradesman (Electrical), Lineman
Cat. Number: 058/2023, 186/2023, 195/2023, 247/2023, 254/2023, 265/2023, 417/2023, 428/2023, 533/2023
Date of Test : 30.04.2024
1. Which of the following statement/s is/are correct regarding electric charge ?
i. Charge is equal to current multiplied by time.
ii. The charge of an electron is equal to 1.602 × 10 -19 C.
iii. Charge is equal to current divided by time.
A) Only i and ii
B) Only ii
C) Only i
d) Only ii and iii
2. Which of the following statement/s is/are correct regarding soldering ?
i. The main constituent elements of solder alloy are tin and lead.
ii. Silver based solders are used to carry out soldering at high temperature.
iii. Flux cannot remove dirt or grease but removes the oxide layer.
A) Only i and ii
B) Only ii and iii
C) Only i
d) i, ii and iii
3. A nichrome wire of 10 cm length and 2 mm diameter has 2Ω resistance. What is the resistance if 30 cm of the same wire is used, assuming temperature to be constant ?
A) 6 Ω
B) 2 Ω
C) 3 Ω
d) 12 Ω
4. Which of the following is/are unit/s of voltage ?
i. Volt
ii. Weber/sec
iii. Weber/m2
A) Only i and iii
B) Only i and ii
C) Only i
d) i, ii and iii
5. Which of the following is/are reason/s for widely using copper as conductor than silver ?
i. Copper has more conductivity than silver.
ii. Copper is cheaper than silver.
A) Only i
B) Only ii
C) Both i and ii
d) None of these
6. Which of the following is/are desirable characteristic/s of insulation materials ?
i. High dielectric strength
ii. low dielectric strength
iii. Flexible
A) Only ii
B) Only i
C) Only i and iii
d) Only ii and iii
7. Which of the following is/are correct regarding semiconductors ?
i. Semiconductors have positive temperature coefficient of resistance.
ii. Silicon, germanium and carbon are examples of semiconductor material.
iii. Valence electrons of semiconductor materials are normally 4.
A) Only ii
B) Only i and iii
C) Only iii
d) Only ii and iii
8. Which of the following is/are correct regarding resistivity ?
i. The unit of resistivity is Siemens per metre.
ii. Resistivity does not depend on the size of conductor.
A) Only i
B) Only ii
C) Both i and ii
d) None of the above
9. If a 16 SWG wire has a cross sectional area of 2 mm2 with a current capacity of 5A, then which of the following statement is true ?
A) An 18 SWG wire has a cross sectional area of 1 mm2 with a current rating of 2.3A
B) An 18 SWG wire has a cross sectional area of 4 mm2 with a current rating of 8.5A
C) An 18 SWG wire has a cross sectional area of 4 mm2 with a current rating of 2.3A
d) An 18 SWG wire has a cross sectional area of 1 mm2 with a current rating of 8.5A
10. Which of the following factors decide the insulation thickness of an electrical cable ?
A) Current
B) Power factor
C) Both A) and B)
d) Voltage
11. A 12V source with an internal resistance of 1W is connected across a load of 5W. Calculate the current through the load.
A) 2.4A
B) 2A
C) 3A
d) 12A
12. Which of the following statement/s is/are correct regarding Kirchoff’s law ?
i. Kirchoff’s current law is applicable for closed loops.
ii. Kirchoff’s current law is applicable for junctions or nodes.
iii. Kirchoff’s voltage law is applicable for closed loops.
iv. Kirchoff’s voltage law is applicable for junctions or nodes.
A) Only ii and iii
B) Only ii and iv
C) Only i and iii
d) Only i and iv
13. Which of the following effects of electric current is utilized for electroplating ?
A) Special rays effect
B) Gas ionization effect
C) magnetic effect
d) Chemical effect
14. Which of the following statement/s is/are correct regarding series and parallel connection of resistance ?
i. The effective resistance of parallel combination of resistance is smaller than the smallest resistance in the combination.
ii. The effective resistance of parallel combination of resistance is larger than the smallest resistance in the combination.
iii. The effective resistance of series combination of resistance is larger than the largest resistance in the combination.
iv. The effective resistance of series combination of resistance is smaller than the largest resistance in the combination.
A) Only ii and iii
B) Only i and iii
C) Only i and iv
d) Only ii and iv
15. Which of the following is/are correct regarding Ohm’s law ?
i. It is applicable when the temperature and other physical conditions do not change.
ii. It is not applicable to non linear devices like Zener diode.
A) Only i
B) Only ii
C) Both i and ii
d) None of these
16. Which of the following properties are correct regarding resistance ?
i. When temperature increases, resistance of pure metals increases normally.
ii. When temperature increases, resistance of insulating materials decreases normally.
iii. Certain alloys such as constantan shows practically no change in resistance for considerable temperature variation.
A) Only i and ii
B) Only i
C) Only ii
d) i, ii and iii
17. Which of the following is/are correct regarding electrochemical cells ?
i. Wet type cells can be operated in both upright and horizontal position.
ii. Voltaic cell is an example of primary cell.
iii. lead acid battery is an example of secondary cell.
A) Only ii and iii
B) Only i and iii
C) Only iii
d) i, ii and iii
18. match the following electrochemical cells with their electrolytes.
1. Carbon Zinc cell
2. mercury cell
3. lead acid battery
i. Ammonium chloride
ii. Sulphuric acid
iii. Potassium Hydroxide
A) 1 – i, 2 – ii, 3 – iii
B) 1 – ii, 2 – i, 3 – iii
C) 1 – i, 2 – iii, 3 – ii
d) 1 – iii, 2 – i, 3 – ii
19. 4 numbers of 12 V, 80 Ah batteries are connected in series. Another 4 numbers of series connected 12 V, 80 Ah batteries are connected parallel to the first set of
series connected batteries. What is the effective voltage and Ampere hour rating of the arrangement ?
A) 48 V, 80 Ah
B) 48 V, 160 Ah
C) 24 V, 80 Ah
d) 24 V, 320 Ah
20. Which of the following statement/s is/are correct regarding maintenance of lead acid battery ?
i. do not overcharge or discharge the battery at high rates as it might cause buckling.
ii. The level of electrolyte should be kept below the plate level.
A) Only i
B) Only ii
C) Both i and ii
d) None of these
21. Which of the following statement/s is/are correct regarding magnetic materials ?
i. Ferromagnetic substances are strongly attracted by a magnet.
ii. Paramagnetic substances are slightly repelled by a magnet.
iii. diamagnetic substances are slightly attracted by a magnet.
A) Only i and ii
B) Only i and iii
C) Only i
d) i, ii and iii
22. match the following magnetic materials and their examples :
1. Ferromagnetic material
2. Paramagnetic material
3. diamagnetic material
i. Iron
ii. Aluminium
iii. Bismuth
A) 1 – i, 2 – ii, 3 – iii
B) 1 – ii, 2 – i, 3 – iii
C) 1 – i, 2 – iii, 3 – ii
d) 1 – ii, 2 – iii, 3 – i
23. Which of the following statement/s is/are correct regarding magnetic effect of electric current ?
i. Greater the current through the conductor, the stronger is the magnetic field produced.
ii. Right hand grip rule can be used to determine the direction of magnetic field around a conductor.
iii. Magnetic field near the conductor is weak and becomes stronger as the distance from conductor increases.
A) Only i and iii
B) Only i and ii
C) Only i
d) i, ii and iii
24. Which of the following is/are unit/s of magnetic flux density ?
A) Weber per metre square
B) Weber
C) Tesla
d) Both A) and C)
25. Which of the following statement/s is/are correct regarding Fleming’s rule ?
i. Fleming’s Right Hand rule is used to determine direction of induced EmF.
ii. Fleming’s Right Hand rule is used to determine the direction of the force acting on the current carrying conductor placed in a magnetic field.
iii. Fleming’s left Hand rule is used to determine direction of induced EmF.
iv. Fleming’s left Hand rule is used to determine the direction of the force acting on the current carrying conductor placed in a magnetic field.
A) Only i and iv
B) Only i and iii
C) Only ii and iv
d) Only ii and iii
26. Which of the following statement/s is/are correct regarding reluctance ?
i. magnetic materials like iron have high reluctance.
ii. Non-magnetic materials have high reluctance.
iii. The reciprocal of reluctance is known as permeance.
A) Only i and iii
B) Only i
C) Only ii and iii
d) Only ii
27. Which of the following is/are correct regarding Faraday’s laws of electromagnetic induction ?
i. EmF is induced in a conductor when there is a relative motion between conductor and magnetic field.
ii. EmF is induced in a conductor when it moves in a direction parallel to the conductor.
iii. EMF is induced in a conductor when it lies in a magnetic field.
A) Only ii and iii
B) Only i
C) Only i and iii
d) i, ii and iii
28. Which of the following factors affect the current through a capacitor ?
i. The frequency of applied voltage.
ii. The capacitance of the capacitor.
iii. The amplitude of the applied voltage.
A) Only i and ii
B) Only iii
C) Only ii and iii
d) i, ii and iii
29. Which of the following capacitors cannot be used in AC circuits ?
A) Electrolytic capacitor
B) mica capacitor
C) Paper capacitor
d) Both B) and C)
30. What is the capacitance of a capacitor that requires 1 mC to charge it to 50 V ?
A) 50 μF
B) 20 μF
C) 20 μF
d) 50 μF
31. What is the working principle of earth resistance tester ?
A) Faraday’s laws of electrolysis
B) Fall of potential method
C) Fleming’s right hand rule
d) Wheatstone bridge
32. The instrument used to measure insulation resistance of a wiring installation
A) Ohm meter
B) multimeter
C) megger
d) Wheatstone bridge
33. In which wiring installation the system earthing is to be done ?
A) Generating stations and substations
B) domestic wiring
C) Industrial wiring
d) Tunnel wiring
34. What is the minimum size of copper plate used in plate earthing ?
A) 600 mm × 600 mm × 3.15 mm
B) 300 mm × 300 mm × 3.15 mm
C) 600 mm × 600 mm × 6.28 mm
d) 300 mm × 300 mm × 6.28 mm
35. What type of lamp holder is commonly used in studios, flood lights and head lights for lamps over 300 watts ?
A) Edison screw type holder
B) Goliath Edison screw type holder
C) Bayonet cap
d) Pendent lamp holder
36. What is the minimum value of insulation resistance of any wiring installation ?
A) 1 Ω
B) 1K Ω
C) 1m Ω
d) 10m Ω
37. As per IE rules the maximum load in a power sub circuit is limited to
A) 1000 watts
B) 2000 watts
C) 3000 watts
d) 5000 watts
38. What is the maximum leakage current in an installation as per IE rules ?
A) 1/500 of full load current
B) 1/5000 of full load current
C) 1/50000 of full load current
d) 1/50 of full load current
39. What type of circuit breaker is typically used for current ratings above 100 Ampere up to 800 Ampere ?
A) mCB
B) ElCB
C) mCCB
d) RCCB
40. The minimum area of cross section of copper conductor in power wiring is
A) 1.5 sq. mm
B) 2.5 sq. mm
C) 3.5 sq. mm
d) 4 sq. mm
41. The direction of emf induced in a DC generator can be find out by which of the following rule ?
A) Fleming’s left hand rule
B) Right hand grip rule
C) Right hand palm rule
d) Fleming’s right hand rule
42. What is the working principle of a dC generator ?
A) Faraday’s laws of electrolysis
B) Fleming’s left hand rule
C) Fleming’s right hand rule
d) Faraday’s laws of electromagnetic induction
43. Calculate the emf generated in a 6 pole lap wound dC generator which has 1000 conductors driven at a speed of 1500 rpm, the flux per pole is 3 milliweber.
A) 75 Volts
B) 150 Volts
C) 225 Volts
d) 240 Volts
44. How many parallel paths in duplex wave winding of an eight pole dC generator ?
A) 2
B) 4
C) 6
d) 8
45. What is the function of split rings of a dC generator ?
A) To increase the output voltage
B) To reduce copper loss
C) To increase the efficiency
D) To ensure constant emf direction
46. The purpose of laminating armature of a dC generator is to
A) Reduce hysteresis loss
B) Increase efficiency
C) Reduce fluctuations in load
D) Reduce eddy current loss
47. To reverse the direction of rotation of a compound motor without changing its characteristics is to change the direction of current of
A) Armature
B) Shunt field
C) Series field
D) Both shunt field and armature
48. Which speed control method offers below normal speed in dC shunt motor ?
A) Field control method
B) Armature control method
C) Voltage control method
d) Ward leonard speed control
49. The connection of hold on coil in a three point starter of a dC shunt motor is
A) In series with armature
B) In series with shunt field
C) In parallel with armature
d) In parallel with supply
50. Which speed control method is applied to obtain both below and above normal speed in a dC motor ?
A) Armature control method
B) Field control method
C) Ward Leonard speed control
D) Tapped field control
51. The displacement of starting and running windings of single phase induction motor is ___________ degree electrical.
A) 45
B) 90
C) 120
d) 180
52. Universal motor is not suitable for the following application
A) Vacuum cleaner
B) Food mixer
C) Portable drilling machine
d) domestic pump motor
53. The rotor of a squirrel cage induction motor is short circuited by using
A) Shading rings
B) End rings
C) Compensating windings
d) None of these
54. What is the speed of stator rotating magnetic field of 3 phase squirrel cage induction motor ?
A) Rotor speed
B) Slip speed
C) Synchronous speed
d) Slightly less than synchronous speed
55. The number of contactors in an automatic star delta starter is
A) 1
B) 2
C) 3
d) 4
56. __________ starter does not reduces starting current.
A) direct on line
B) Star delta
C) Auto-transformer
d) Rotor resistance
57. Slip ring induction motor is started by using ________ starter.
A) direct on line
B) Star delta
C) Rotor resistance
d) All the above
58. The function of ferrule in panel board is to identify
A) Panel
B) Cable
C) Earth
d) Switch
59. The accessory used to hold and insulate the cable while passing through drilled holes in a panel is
A) Wire clip
B) Sleeve
C) Thimble
d) Grommet
60. The direction of rotation of a three phase squirrel cage induction motor is reversed by
A) Cascade control
B) Changing applied frequency
C) Interchanging any two phases
d) All the above methods
61. Watt meter is a/an _________ instrument.
A) Indicating
B) Integrating
C) Recording
d) None of these
62. Which effect of electric current is utilised in moving iron type instrument to produce deflecting torque ?
A) Heating
B) magnetic
C) Chemical
d) Ionisation
63. The material used for making springs in spring controlled instruments must have
A) Low specific resistance
B) Non-magnetic
C) Low temp. coefficient of resistance
D) All the above
64. The torque required in an indicating instrument to bring the pointer quickly to rest in its deflected position to obtain quick and accurate reading is
A) Deflecting torque
B) Controlling torque
C) damping torque
d) None of these
65. ________ type instrument measures AC quantities only.
A) moving coil
B) moving iron
C) dynamometer
d) Induction
66. What is the working principle of two winding transformer ?
A) Self induction
B) mutual induction
C) Electromagnetic drag
d) Conduction
67. In a transformer, which factor remains the same when transformer action takes place ?
A) Current
B) Voltage
C) Frequency
d) Temperature
68. Which of the following statement is false about a transformer ?
A) The per turn induced emf of primary and secondary are different
B) The magnitude of induced emf is directly proportional to number of turns in the respective winding
C) The magnitude of induced emf is directly proportional to supply frequency
d) Transformation ratio of step up transformer is greater than one
69. In order to operate two single phase transformers in parallel which factor/factors must be kept same ?
A) Polarity
B) Voltage ratios
C) Percentage impedance
d) All the above
70. Transformer oil is filled in the transformer tank for
A) Cooling the windings
B) Insulating the windings
C) Cooling and insulating the windings
d) Preventing moisture entry into the tank
71. The unit of lamp efficiency is
A) lumen second
B) lumen
C) lumen per watt
d) lux
72. If the distance between the surface and the light source is doubled, illumination of the surface becomes
A) double
B) Quadruple
C) Half
d) One fourth
73. The function of choke in fluorescent tube light is
A) Surge voltage and limit current
B) High voltage and increase current
C) low voltage and limit current
d) low voltage and increase the current
74. The mercury vapour lamp gives
A) Red-orange glow
B) Greenish blue light
C) yellow light
d) White light
75. The sweep of the ceiling fan is determined by
A) Speed of the fan
B) mounting height of fan
C) diameter of the circle formed by the blade tip of fan
d) All of these
76. The knee voltage of a silicon diode is
A) 0.2
B) 0.3
C) 0.5
d) 0.7
77. doping element of N-type semiconductor is
A) Aluminium
B) Gallium
C) Antimony
d) Indium
78. The ripple factor of a single phase full wave bridge rectifier is
A) 0.482
B) 0.812
C) 1.11
d) 1.21
79. The emitter of a transistor is _________ doped.
A) Heavily
B) moderately
C) lightly
d) None of these
80. In a full wave bridge rectifier, the current in each diodes flows for
A) The complete cycle of the input signal
B) Half cycle of the input cycle
C) more than half cycle of the input signal
d) None of these
81. Identify the non-renewable resource from the following.
A) Solar
B) Natural gas
C) Geothermal
d) Hydro
82. Solar cells are made of
A) Aluminum
B) Germanium
C) Silicon
d) Cadmium
83. Fuel used in nuclear reactors are
A) Co-60
B) U-235
C) I-131
d) U-238
84. The power generation in a windmill depends on
A) Wind velocity
B) Height of tower
C) Thickness of blade
d) Shape of blade
85. The principle on which solar cell works
A) Opto coupling
B) Isolation
C) Photovoltaic
d) Black body radiation
86. The use of economizer in thermal power plant is
A) Heat up feed water
B) Heat up the fuel
C) Cool the pulverized fuel
d) Heat up incoming air
87. In hydro-electric power plant, the surge tank is used to
A) Supply water at constant pressure
B) Relieve water hammer pressure in penstock pipe
C) Produce surge in the pipeline
d) None of these
88. What is the approximate efficiency of a typical thermal power station ?
A) 26 – 36%
B) 45 – 55%
C) 55 – 65%
d) 65 – 75%
89. The graphical representation of the discharge and time is known as
A) load curve
B) monograph
C) Hector graph
d) Hydro graph
90. For high head low discharge hydel power plant the water turbine used is
A) Pelton wheel
B) Fransis turbine
C) Propeller turbine
d) Kaplan turbine
91. The copper loss in transformer can be reduced by
A) Changing the core materials
B) laminating the core
C) Reducing the resistance of the winding
d) All of the above
92. Guy wire is employed for
A) Providing protection against surges
B) Supporting the pole
C) Providing emergency earth route
d) None of the above
93. The highest transmission voltage used in India is
A) 132 kV
B) 220 kV
C) 440 kV
d) 765 kV
94. The length of short transmission line is up to
A) 50 km
B) 100 km
C) 120 km
d) 200 km
95. If the length of a single core underground cable is doubled, its capacitance becomes
A) doubled
B) Halved
C) Quadrupled
d) No change
96. Skin effect in an AC transmission system depends on which of the following ?
i. Nature of material
ii. diameter of wire
iii. Frequency
iv. Shape of wire
A) i, iii
B) i, ii, iii
C) i, iii, iv
d) i, ii, iii, iv
97. Back to back dC link is used to connect
A) long distance dC transmission line
B) Transmit large block of relatively cheap power from remote source
C) Couple two AC system at different frequencies
d) None of the above
98. The dC ring main distribution system is used because of
A) Good voltage regulation
B) more reliable than others
C) Both A) and B)
d) None of the above
99. The neutral current of balanced 3 phase 4 wire system is
A) Zero
B) Increase with load
C) decreases with load
d) None of the above
100. Which of the following is not an advantage of a dC transmission line ?
A) low corona loss and radio interference
B) Greater reliability
C) Require high reactive power to transmit over dC line
d) None of the above
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