Lineman - Question and Answer Key

Name of Post: Lineman

 Department: PWD (Electrical Wing)

 Cat.No: 258/2021

 Date of Test: 19.12.2021

Question Code: 131/2021


 1. Which law states that in closed electric circuit the applied voltage is equal to the sum of the voltage drops?
(A) Ohm's law
(B) Law of resistance
(C) Kirchhoff's first law
(D) Kirchhoff's second law

2. What is the formula for Quantity of electricity (Q) ?
(A) Current x Time
(B) Voltage x Current
(C) Current x Resistance
(D) Voltage x Resistance

3. Which one defines the change in resistance in Ohm (Ω) per degree centigrade (°C)?
(A) Temperature effect
(B) Laws of temperature
(C) Temperature constant
(D) Temperature coefficient

4. Resistance of 250V, 100W lamp will be_______
(A) 0.4 Ω
(B) 25 Ω
(C) 625 Ω
(D) 2.5 Ω

5. The resistivity of conductor ________
(A) Decreases with increase of temperature
(B) Increases very slowly by increasing the temperature
(C) Increases sharply by increasing the temperature slightly
(D) Increases very sharply in proportion to the temperature

6. The reciprocal of resistance is _______
(A) Conductance
(B) Susceptance
(C) Impedance
(D) Reactance

7. What are the three factors essential to make a simple electric circuit?
(A) Switch, Voltage, Fuse
(B) Current, Fuse, Conductor
(C) Electromotive force, Current, Resistance
(D) Potential difference, Quantity of electricity, Resistance

8. If short circuit is occurred in an electric circuit, then the value of resistance will be ______
(A) Low
(B) High
(C) Zero
(D) Infinity

9. The current in a series circuit is _______
(A) Same throughout the circuit
(B) Sum of individual resistor's current
(C) Depends Individual resistance value
(D) Calculated by product of resistance and voltage

10. The low value resistance can be measured by ___________
(A) Series ohm meter
(B) Substitution method
(C) Kelvin bridge method
(D) Wheatstone bridge method

11. As per Ohm's law the current is ______
(A) Directly proportional to the voltage
(B) Inversely proportional to the voltage
(C) Directly proportional to the resistance
(D) Inversely proportional to the temperature

12. Ohm's law states the relation between ______
(A) Current, E.M.F. and Voltage
(B) E.M.F. Current and Resistance
(C) Temperature, E.M.F. and Resistance
(D) Voltage, Specific resistance and Resistance

13. The formula to find the current (I) as per Ohm's law is _______
(A) I =R/V
(B) I= V R²
(C) l=V/R
(D) I=VR

14. What is the change of resistance value of the conductor as its diameter is doubled?
(A) Increases to two times
(B) Decreases to four times
(C) Decreases to half of the value
(D) No change in value of the resistance

15. What is the value of resistance in an open circuit ?
(A) Zero
(B) Low
(C) High
(D) Infinity

16. The parallel circuit is used for__________
(A) House wiring
(B) Continuity test
(C) Decorative lighting
(D) Ammeter connection

17. Which is the application of series circuit?
(A) Fuse in circuit
(B) Voltmeter connection
(C) Electrical lamp in houses
(D) Shunt resistor in ammeter

18. In Ohm's law the condition is that
(A) The temperature should vary
(B) The temperature should remain constant
(C) Current should be proportional to voltage
(D) Ratio of V/I should be constant

19. The resistance of a conductor on increasing the temperature
(A) Decreases
(B) Remains constant
(C) Increases
(D) Varies

20. In a parallel circuit across each resistance
(A) Current divides and voltage remains the same
(B) Voltage divides and Current remains the same
(C) Both divide
(D) Both remains the same

21. The property of a material which opposes the creation of magnetic flux in it is known as
(A) Magnetomotive force
(B) Reluctance
(C) Permeance
(D) Reluctivity

22. Reciprocal of reluctance is
(A) Susceptibility
(B) Permeability
(C) Permeance
(D) Reluctivity

23. Direction of forces on a conductor in a magnetic field is determined by_______
(A) Fleming's right hand rule
(B) Fleming's left hand rule
(C) Right hand thumb rule
(D) None of the above

24. A property of material which opposes the creation of magnetic flux in it is known as _______
(A) Magnetomotive force
(B) Reluctance
(C) Permeance
(D) Reluctivity

25. In electrical machines laminated cores are used with a view to reducing______
(A) Hysteresis loss
(B) Eddy current loss
(C) Copper loss
(D) All of the above

26. The magnitude of induced is directly proportional to the
(A) Rate of change of current
(B) Rate of change of flux linkage
(C) Constant value of current
(D) Constant value of flux linkage

27. Static electromagnetic induction is adopted in_________
(A) Generators
(B) Alternators
(C) Transformers
(D) All of the above

28. Eddy currents produced in a core______
(A) Increase useful energy
(B) Create loss of useful energy
(C) Strengthen the magnetic field
(D) None of the above

29. For an inductance current is proportional to_______
(A) Magnetic field
(B) Voltage across the inductance
(C) Both magnetic field and voltage across the inductance
(D) Neither magnetic field nor voltage across the inductance

30. The electrical current is analogous to the magnetic circuit
(A) Flux
(B) Reluctance
(C) Flux density
(D) Permeability

31. Electric current is defined as_____
(A) Flow of electrons in a conductor
(B) Resistance offered in a circuit
(C) Potential difference in a circuit
(D) Electrons in atomic structure

32. What is the polarity of an AC source?
(A) Positive to ground
(B) Negative to positive
(C) Positive to negative
(D) Change at regular intervals

33. What is the standard domestic supply voltage in India as per Indian standard?
(A) 240 V
(B) 230 V
(C) 220 V
(D) 250 V

34. Why AC transmission is preferred to long distance than DC?
(A) Less line losses
(B) It is easily available
(C) Easy to carry high current
(D) Current carrying capacity is more

35. How much time is required by 50Hz AC supply to complete one cycle?
(A) 0.1 second
(B) 0.02 second
(C) 0.15 second
(D) 0.45 second



37. In an A.C. circuit, a low value of kVAR compared with kW indicates________
(A) Unity p.f.
(B) High p.f.
(C) Low efficiency
(D) None of these

38. In an AQ.C. circuit, the ratio of kW/kVA represents_______
(A) Form factor
(B) Power factor
(C) Load factor
(D) None of these

39. In A.C. circuits, laminated iron is used to ________
(A) Reduce eddy current loss
(B) Reduce circuit permeability
(C) Make assembly cheap
(D) Increase heat radiation

40. An alternating current or voltage is that which
(A) Changes in direction only
(B) Changes in magnitude only
(C) Changes in both magnitude and direction
(D) Has a random movement of electrons

41. Compound generator is a
(A) Separately excited generator
(B) Self excited generator
(C) Series generator
(D) Shunt generator

42. In DC lap winding number of parallel path A =
(A) P
(B) Z
(C) 60
(D) N

43. What is the emf in a 6 pole lap wound armature having 18 slots, 2 conductor per slot shaft rotating at 100 RPM, flux per pole is 0.1 Wb?
(A) 6V
(B) 36V
(C) 18V
(D) 60V

44. As per Fleming's right hand rule, middle finger points the direction of
(A) Induced emf
(B) Motion of conductor
(C) Flux
(D) None of the above

45. Load current of a DC series generator is
(A) equal to shunt field current
(B) equal to series field current
(C) sum of series and shunt field currents
(D) sum of series field and armature currents

46. In along shunt compound DC generator the shunt field winding is connected in parallel with
(A) Series field
(B) Armature
(C) Parallel connected armature and series field combination
(D) Series connected armature and series field combination

47. The direction of rotation of DC motor can't change by
(A) Changing direction of Armature current
(B) Changing direction of field current
(C) Changing the direction of both armature and field currents
(D) Changing the direction of supply voltage

48. Speed of a DC motor
(A) Directly proportional to flux
(B) Directly proportional of back emf
(C) Inversely proportional to supply voltage
(D) Can't change by increasing supply voltage

49. Shaft torque in DC motor is
(A) less than armature torque
(B) greater than armature torque
(C) equal to armature torque
(D) square of armature torque

50. A DC shunt motor is connected with 200V DC supply. It takes a line current of 18A. What will be the Armature current if shunt field resistance is 100 Ω?
(A) 36A
(B) 2A
(C) 20A
(D) 16A

51. The motor used in mixer grinder
(A) Stepper motor
(B) Universal motor
(C) Capacitor start motor
(D) Compound motor

52. An Induction motor with 6 poles rotating at a speed of 950 rpm using 50 Hz supply. The percentage of slip is
(A) 5%
(B) 3%
(C) 15%
(D) 0.5%

53. D.O.L. starter is used to start the motor up to
(A) 25 HP
(B) 5 HP
(C) 7.5 HP
(D) 100 HP

54. In slip ring induction motor starter 3 external variable resistances are
(A) Connected in Series with stator circuit
(B) Connected in Parallel with stator circuit
(C) Connected in Star with rotor circuit
(D) Connected in Delta with rotor circuit

55. Which of the following is suitable for starting squirrel cage induction motor?
(A) Rotor resistance starter
(B) 4 point starter
(C) 3 point starter
(D) Auto transformer starter

56. DIN rail is used to mount
(A) Push button switches
(B) Circuit breakers
(C) Indicating lamps
(D) Kit Kat fuses

57. Which of the following is not a method of synchronisation?
(A) Dark lamp method
(B) Bright lamp method
(C) Dark and bright lamp method
(D) MMF method

58. Centrifugal switch in a centrifugal pump motor is used to control
(A) Supply through the starting winding
(B) Supply through the running winding
(C) Speed of the pump motor
(D) Overload current

59. Speed of a SCIM can be changed by
(A) Varying number of poles
(B) Varying supply phase sequence
(C) Interchanging any two motor terminals
(D) None of the above

60. Growler is a
(A) Armature testing machine
(B) Earth testing machine
(C) Coil winding machine
(D) Polarity testing machine

61. Moderator is a part of
(A) Tidal power plant
(B) Solar power plant
(C) Windmill
(D) Nuclear power plant

62. The part which reduces the water hammering effect in hydroelectric power plant system
(A) Reservoir
(B) Tail race
(C) Surge tank
(D) Pen stock

63. Demand factor X connected load =
(A) Average load
(B) Power plant capacity
(C) Maximum demand
(D) Average demand

64. Solar PV. module efficiency will always be
(A) greater than cell efficiency
(B) less than cell efficiency
(C) equal to cell efficiency
(D) above 1

65. Service lines are the part of
(A) Primary transmission
(B) Secondary transmission
(C) Primary distribution
(D) Secondary distribution

66. Solar panel output does not depend on
(A) Geographical location
(B) Season of the year
(C) Time of the day
(D) AH capacity of connected battery

67. Example for non-conventional energy source
(A) Coal
(B) Natural gas
(C) Sun
(D) Petroleum

68. Conducting media in MHD Tunnel is
(A) Hydrogen
(B) Plasma
(C) Solid conductor
(D) Super conductor

69. An 8 pole alternator produces 50 Hz supply. What will be the speed in rpm?
(A) 750
(B) 190
(C) 1500
(D) 1200

70. Unit of solar irradiance is
(A) m²/W
(B) W²/m
(C) W/m²
(D) m/W²

71. Advantage of D.C. Transmission system
(A) No inductance
(B) No phase displacement
(C) Better voltage regulation
(D) All of the above

72. Skin effect of a conductor
(A) Increases with increase in diameter
(B) Inversely proportional to frequency
(C) More in stranded condition
(D) Less in solid condition

73. Which is provided to prevent the entry of moisture in UG cables?
(A) Bedding
(B) Armouring
(C) Metallic sheath
(D) Serving

74. Value of fusing factor is always
(A) less than fusing current
(B) less than one
(C) more than fusing current
(D) greater than one

75. Which effect is accompanied by the production of ozone in OH line?
(A) Skin effect
(B) Corona effect
(C) Proximity effect
(D) Ferranti effect



77. Buchholz relay is located
(A) In the main tank
(B) In between conservator tank and main tank
(C) In the breather
(D) In between conservator and breather

78. It gives support to the pole against falling
(A) Lightning arrestor
(B) Stay set
(C) Cross arm
(D) Earth wire

79. Most of the substations are used to
(A) Increase the power
(B) Change the frequency
(C) Change the voltage
(D) Decrease the power

80. Horn gap type surge diverter is a
(A) Lightning arrester
(B) Voltage regulator
(C) Overload tripping contact
(D) Air break circuit breaker

81. The transistor configuration used for impedance matching is
(A) CE
(B) CB
(C) CC
(D) All of the above

82. In PN junction diode the depletion region contains
(A) Electrons
(B) Holes
(C) Immobile ions
(D) None of the above

83. Peak inverse voltage of centre tapped full wave rectifier is
(A) Vm
(B) 2Vm
(C) Vm/2
(D) Vm/√2

84. When transistor is used as a switch its region of operation is
(A) Active region
(B) Cut-off region
(C) Saturation region
(D) Both B and C

85. The forbidden energy gap for silicon semiconductor is
(A) 1.21 eV
(B) 0.72 eV
(C) 0.3 eV
(D) 5 eV

86. The rectification efficiency of a half wave rectifier is
(A) 81.2%
(B) 40.6%
(C) 0.48%
(D) 1.21%

87. Unit of luminous flux is
(A) lux
(B) lumen
(C) lumen-hours
(D) lumen/m²

88. The material which can be used for filaments of incandescent lamps must possess
(A) high melting point
(B) low vapour pressure
(C) high resistivity
(D) All of the above

89. According to inverse square law, the illumination of a surface is
(A) directly proportional to distance between surface and the source
(B) directly proportional to square of distance between surface and the source
(C) inversely proportional to square of distance between surface and the source
(D) inversely proportional to distance between surface and the source

90. Electric motor used in mixer grinder is
(A) universal motor
(B) capacitor start induction motor
(C) shaded pole motor
(D) shunt motor

91. Which one of the following is an indicating type Instrument?
(A) Voltmeter
(B) Ammeter
(C) Energy meter
(D) Both (A) and (B)

92. The instrument that totalizes events over a specific period of time is called
(A) Recording instrument
(B) Indicating instrument
(C) Integrating instrument
(D) None of the above

93. Induction type measuring instruments are used for
(A) AC measurements only
(B) DC measurements only
(C) Both AC and DC measurements
(D) None of the above



95. Which one of the following is a disadvantage of PMMC (permanent magnet moving coil instrument)?
(A) PMMC can be modified into Ammeter and voltmeter.
(B) PMMC exhibits no hysteresis.
(C) Operation of PMMC is not significantly affected by stray magnetic field.
(D) Errors due to ageing of control spring and the permanent magnet.

96. Which of the following parameters remains unchanged between primary and secondary windings of a step up transformer?
(A) Voltage
(B) Current
(C) Resistance
(D) Frequency

97. Which one the following is NOT a criterion for the parallel operation of transformer?
(A) The transformers are to be connected properly so that the net voltage around the local loop is not zero.
(B) Three phase transformers must have zero relative phase displacement on the secondary sides.
(C) The transformers must have same voltage ratio to avoid no load circulatiing current.
(D) There should exist only a limited disparity in the per unit impedances of the transformers.

98. A 20 kVA, 50 Hz, 2000/200V distribution transformer has primary turns of 200. The maximum flux in the core is given by_______ webers.
(A) 0.09
(B) 0.045
(C) 0.0225
(D) 0.2

99. Which of the following cooling methods is used for very large size transformers?
(A) Natural cooling
(B) Oil to air heat exchanger unit
(C) Oil to water heat exchanger unit
(D) None of the above

100. The fusing characteristic is a curve between
(A) Fusing time and voltage.
(B) Fusing time and percentage of fuse current.
(C) Fusing time and Temperature.
(D) Fusing time and material type.

No comments:

Post a Comment