SSC Junior Engineer Electrical Online Exam 2017 CPWD/CWC/MES Electrical Engineering 1-03-2017 Evening

1. Generally an electrolytic capacitor is made to provide. ?

A) Low capacitance
B) Large value of capacitance
C) Variable capacitance
D) Fixed capacitance

... Answer is D)
Explanation will provide as soon as possible.

2. Voltage applied across a ceramic dielectric produces an electrostatic field 100 times greater than in air. The dielectric constant of the ceramic equals . ?

A) 1/100
B) 100/3
C) 50
D) 100

... Answer is D)
Explanation will provide as soon as possible.

3. Which of the following capacitors of identical rating will have the smallest dimensions ?

A) Mica capacitor
B) Aluminum foil capacitor
C) Ceramic capacitor
D) Paper capacitor

... Answer is C)
Explanation will provide as soon as possible.

4. Internal heating of capacitor is usually attributed to . ?

A) Electron movement
B) Leakage resistance
C) Dielectric charge
D) Plate vibration

... Answer is B)
Explanation will provide as soon as possible.

5. During discharge of a battery.. ?

A) The voltage of cell increases
B) The voltage of cell decreases
C) The voltage of cell increases
D) None of these

... Answer is B)
Explanation will provide as soon as possible.

6. Which efficiency of the battery is more ?

A) Overall efficiency
B) Ampere hour efficiency
C) Watt hour efficiency
D) M S

... Answer is B)
Explanation will provide as soon as possible.

7. A wire bent into a semi–circle in the centre and straight at both ends is placed in a uniform magnetic field B pointing out of the page shown in the figure. If the wire carries current I, the force on each straight section xy and zw is ?

A) IB (Length × Magnetic Field)
B) IB(current × Magnetic field)
C) IlB (current × Length× Magnetic Field)
D) Zero

... Answer is C)
Explanation will provide as soon as possible.

8. If three 30µF capacitors are connected in series, the net capacitance is ?

A) 10µF
B) 60µF
C) 90µF
D) None of these

... Answer is A)
Explanation will provide as soon as possible.

9. For making capacitors, it is better to select a dielectric having .. ?

A) Low permittivity
B) High permittivity
C) Permittivity same as that of air
D) None of these

... Answer is B)
Explanation will provide as soon as possible.

10. The materials having low retentivity are suitable for making ?

A) Temporary magnets
B) Weak magnets
C) Permanent magnets
D) None of these

... Answer is A)
Explanation will provide as soon as possible.

11. In a parallel circuit operating with a source of 30 V AC, designed to carry a total current of 6A, what happens to the protection device (fuse) when the resistance suddenly change to 2Ω 30 V ?

A) It closes
B) It opens
C) It shorts to ground
D) There is no change

... Answer is B)
Explanation will provide as soon as possible.

12. Which of the following determines total power in a series circuit ?

A) Current flowing through a switch
B) Total voltage applied to the circuit
C) Source voltage times the current
D) Average of the wattage consumed by each resistor

... Answer is C)
Explanation will provide as soon as possible.

13. What should be observed when connecting a voltmeter into a DC circuit ?

A) Resistance
B) RMS
C) Power factor
D) Polarity

... Answer is D)
Explanation will provide as soon as possible.

14. A potential divider is normally connected.. ?

A) At a distance V/100 metres from the generator where V is the voltage to be measured in KV
B) Outside the generator circuit towards the load circuit
C) Within the generator circuit
D) None of these

... Answer is B)
Explanation will provide as soon as possible.

15. In a pure inductive circuit... ?

A) The current lags applied voltage by 90 degree
B) The current is in phase with applied voltage
C) The current leads applied voltage by 90 degree
D) None of these

... Answer is A)
Explanation will provide as soon as possible.

16. The average power in a pure inductive circuit is ?

A) √3VI cos φ
B) VI cos φ
C) VI
D) 0

... Answer is D)
Explanation will provide as soon as possible.

17. In a R–L series circuit the power factor P.F. is ?

A) Lagging
B) Leading
C) 1
D) 0

... Answer is A)
Explanation will provide as soon as possible.

18. The angle of a series R–L–C circuit is leading if... ?

A) R = 0
B) XL = 0
C) XC < XL
D) XC > XL

... Answer is D)
Explanation will provide as soon as possible.

19. In an R–C–L series circuit, during resonance, the impedance will be . ?

A) Zero
B) Minimum
C) Maximum
D) None of these

... Answer is B)
Explanation will provide as soon as possible.

20. Kirchoff's current law (KCL) is applicable only to ?

A) Closed loops in a network
B) Electronic circuits
C) Electric circuits
D) Junction in a network

... Answer is D)
Explanation will provide as soon as possible.

21. Flow of electrons in the circuit constitutes ?

A) An e.m.f
B) An electric current
C) Magnetic charge
D) None of these

... Answer is B)
Explanation will provide as soon as possible.

22. The material used for the magnetic circuit where high value of flux density required is ?

A) Ferro cobalt
B) Cast iron
C) Soft steel
D) Gray cast iron

... Answer is A)
Explanation will provide as soon as possible.

23. If two resistance of 10Ω and 10Ω are connected in parallel the equivalent resistance is ?

A) 1Ω
B) 5Ω
C) 15Ω
D) 100Ω

... Answer is B)
Explanation will provide as soon as possible.

24. Unit of magnetic flux is ?

A) Werber/m2
B) Coulomb
C) Amprere–turn
D) Weber

... Answer is D)
Explanation will provide as soon as possible.

25. Fleming's left hand rule is used to find ?

A) Direction of force on a current carrying conductor in a magnetic field
B) Direction of flux in a solenoid
C) Polarity of magnetic pole
D) Direction of magnetic field due to a current carrying conductor in a magnetic field

... Answer is A)
Explanation will provide as soon as possible.

26. In which of the following voltage source is the movement of conductors in a magnetic field used to produce voltage ?

A) In a thermo couple
B) In a zinc copper element
C) In a D.C. generator
D) In a transformer

... Answer is C)
Explanation will provide as soon as possible.

27. The relative permeability of a material is 0.95. The material is ?

A) Diamagnetic
B) Paramagnetic
C) Ferromagnetic
D) None of these

... Answer is A)
Explanation will provide as soon as possible.

28. The series magnet of a single phase Energy meter consists of coil of ?

A) Thin wire of few turns
B) Thick wire of few turns
C) Thick wire of more turns
D) Thin wire of more turns

... Answer is B)
Explanation will provide as soon as possible.

29. The relative permeability of paramagnetic material is ?

A) Less than unity
B) Equal to unity
C) Greater than unity
D) None of these

... Answer is C)
Explanation will provide as soon as possible.

30. Reluctance offered by the magnetic circuit depends upon ?

A) Nature of magnetic material
B) Length of magnetic flux path
C) Cross–sectional area of the material
D) All options are correct

... Answer is D)
Explanation will provide as soon as possible.

31. Magnetic recording tape is most commonly made from ?

A) Small particles of iron
B) Silicon–iron
C) Ferric oxide
D) None of these

... Answer is C)
Explanation will provide as soon as possible.

32. Moving iron meters can be used to measure ?

A) Only AC
B) Only DC
C) Both AC and DC
D) None of these

... Answer is C)
Explanation will provide as soon as possible.

33. A network has 10 nodes and 17 branches. The number of different node pair voltage would be ?

A) 7
B) 9
C) 10
D) 45

... Answer is D)
Explanation will provide as soon as possible.

34. Find current l1, l2 and l3 respectively in the given figure. ?

A) 1.38A, 1.1A and 5.52 A
B) 1.38A, 5.5A and 1.1 A
C) 1.38A, 0.9A and 6.38 A
D) 1.1A, 5.52A and 1.38 A

... Answer is A)
Explanation will provide as soon as possible.

35. In the below network effective resistance existing across the voltage source is ?

A) 1Ω
B) 2Ω
C) 3Ω
D) 4Ω

... Answer is C)
Explanation will provide as soon as possible.

36. Which one of the following is applicable to any network linear or non–linear, active or passive, time varying or invariant as long as Kirchhoff's laws are not violated ?

A) Tellegen's theorem
B) Reciprocity theorem
C) Maximum power transfer theorem
D) Superposition theorem

... Answer is A)
Explanation will provide as soon as possible.

37. In which of the following, it is not desired to attain the condition of maximum power transfer ?

A) Electronic circuits
B) Communicational circuits
C) Computer circuits
D) Electric circuits

... Answer is D)
Explanation will provide as soon as possible.

38. A current mirror can be used as an active load because ?

A) It has low AC resistance
B) It has high AC resistance
C) It has high DC resistance
D) It has low DC resistance

... Answer is B)
Explanation will provide as soon as possible.

39. In the below given network, the ideal closed loop voltage gain is ?

A) -1
B) 1
C) 50
D) ∞

... Answer is B)
Explanation will provide as soon as possible.

40. If the capacitor of a single phase motor is short circuited, the motor will ?

A) Start
B) No start
C) Start with jerks
D) Start and then stop

... Answer is B)
Explanation will provide as soon as possible.

41. The speed of the rotating magnetic field in an induction motor is known as the ?

A) Slip speed
B) Effective speed
C) Shaft speed
D) Synchronous speed

... Answer is D)
Explanation will provide as soon as possible.

42. Which of the following is essential for the reciprocity theorem to be applicable ?

A) Linearity
B) Bilateralism
C) No initial history
D) All options are correct

... Answer is D)
Explanation will provide as soon as possible.

43. When the frequency of the rotor of an induction motor is small, it can be measured by ?

A) D.C. moving coil milli–voltmeter
B) Galvanometer
C) D.C. moving coil ammeter
D) A.C. voltmeter

... Answer is A)
Explanation will provide as soon as possible.

44. The value of the capacitor in a capacitor start motor controls the ?

A) Starting torque
B) Speed of the motor
C) Efficiency
D) None of these

... Answer is A)
Explanation will provide as soon as possible.

45. In the below given torque/speed characteristics of an induction motor, stable region is ?

A) X
B) Y
C) Z
D) W

... Answer is D)
Explanation will provide as soon as possible.

46. Which of the following is most economical method for starting single–phase motor ?

A) Capacitor start method
B) Split–phase method
C) Induction–start method
D) Resistance–start method

... Answer is A)
Explanation will provide as soon as possible.

47. What is the use of the circuit shown in the figure below ?

A) To reduce the starting current to a very low
B) To achieve a smooth starting
C) To attain a higher starting torque
D) To attain a higher maximum torque

... Answer is B)
Explanation will provide as soon as possible.

48. Which of the following motors is represented by the characteristics curve shown below ?

A) D.C. shunt motor
B) D.C series motor
C) D.C. compound motor
D) Asynchronous motor

... Answer is D)
Explanation will provide as soon as possible.

49. For a 100% efficient transformer, the primary winding has 1000 turns and the secondary 100 turns. If the power input to the above transformer is 1000 watts, the power output is ?

A) 1000 watts
B) 100 watts
C) 10 watts
D) 10 kW

... Answer is A)
Explanation will provide as soon as possible.

50. What is the efficiency of transformer compared with that of electrical motors of the same power ?

A) Much smaller
B) Somewhat smaller
C) About same
D) Much higher

... Answer is D)
Explanation will provide as soon as possible.

51. In a common emitter amplifier, the un– bypassed emitter resistance provides ?

A) Voltage–shunt feedback
B) Current series feedback
C) Negative–voltage feedback
D) Positive–voltage feedback

... Answer is C)
Explanation will provide as soon as possible.

52. Which input yields natural response ?

A) Step input
B) Sinusoidal input
C) Impulse input
D) Ramp input

... Answer is C)
Explanation will provide as soon as possible.

53. The voltage of a circuit is measured by a voltmeter having input impedance comparable with the output impedance of the circuit thereby causing error in voltage measurement. This error may be called as ?

A) Gross error
B) Random error
C) Error caused by misuse of instrument
D) Error caused by loading effect

... Answer is D)
Explanation will provide as soon as possible.

54. Which of the following options is an Active transducer ?

A) Photo emissive cell
B) Photo voltaic cell
C) Photo emissive cell, photo voltaic cell and selsyn
D) Selsyn

... Answer is B)
Explanation will provide as soon as possible.

55. Un–bonded strain gauges are ?

A) Exclusively used for transducer applications
B) Exclusively used for stress analysis
C) Used for unbounded strains only
D) None of these

... Answer is A)
Explanation will provide as soon as possible.

56. Dynamometer type moving coil instruments are provided with ?

A) Eddy current damping
B) Pneumatic damping
C) Fluid friction damping
D) Electrostatic damping

... Answer is B)
Explanation will provide as soon as possible.

57. Voltmeter is a galvanometer with ?

A) High resistance
B) Low resistance
C) Both low and high resistance
D) Uncertain resistance

... Answer is A)
Explanation will provide as soon as possible.

58. Strain gauge rosettes are used when ?

A) The direction of hoop stress is not known
B) The direction of principal stress is not known
C) The direction of principal stress is known
D) The direction of longitudinal stress is not known

... Answer is B)
Explanation will provide as soon as possible.

59. The dead time of an instrument refers to ?

A) Large change of input quantity for which there is no output.
B) The time encountered when the instrument has to wait for some reactions to take place
C) The time before the instrument begins to response after the quantity has altered
D) Retardation or delay in the response of an instrument to a change in the input signal

... Answer is C)
Explanation will provide as soon as possible.

60. One input terminal of high gain comparator circuit is grounded and a sinusoidal voltage is applied to the other input. The output of comparator will be ?

A) A sinusoidal
B) A full rectified sinusoidal
C) A half rectified sinusoidal
D) A square wave

... Answer is D)
Explanation will provide as soon as possible.

61. A minimum – phase system with no zeros has a phase–angle of –270° at gain crossover frequency. The system is ?

A) Stable
B) Unstable
C) Marginally stable
D) Conditionally stable

... Answer is B)
Explanation will provide as soon as possible.

62. Transfer function of a system is G(s) = K/[s2 (1 + sT)]. This open–loop system is ?

A) Stable
B) Unstable
C) Marginally stable
D) Conditionally stable

... Answer is B)
Explanation will provide as soon as possible.

63. In a closed–loop system in which the output is the speed of a motor, the output rate control can be used to ?

A) Limit the speed of the motor
B) Limit the torque output of motor
C) Limit the acceleration of the motor
D) Reduce the damping of the system

... Answer is C)
Explanation will provide as soon as possible.

64. If an input signal with non–zero direct current (dc) component is applied to a low pass RC network, then DC component in the output signal will be ?

A) The same as that in the input
B) Less than that in the input
C) More than that in the input
D) zero

... Answer is A)
Explanation will provide as soon as possible.

65. A freshly painted layer may be dried electronically by ?

A) Convective heating
B) Induction heating
C) Dielectric heating
D) Emissive heating

... Answer is C)
Explanation will provide as soon as possible.

66. An OP AMP has an offset voltage of 1 mV and is ideal in all other respects. If this OP AMP is used in the circuit shown in the figure, the output voltage will be approximately ?

A) N m
B) R K
C) A S
D) M S

... Answer is A)
Explanation will provide as soon as possible.

67. Two heaters rated at 1000W, 250 each are connected in series across a 250V, 50Hz ac mains. The total power drawn from the supply would be ?

A) 2000
B) 1000
C) 500
D) 250

... Answer is C)
Explanation will provide as soon as possible.

68. What is the maximum length of the flexible conduit in motor installation ?

A) Less than 1.25m
B) Less than 2.25m
C) Less than 3.5m
D) Can exceed not more than 5 m 5 m

... Answer is A)
Explanation will provide as soon as possible.

69. Which among these fuse is very fast in operation ?

A) Semiconductor fuses
B) High rupturing capacity type
C) Cartridge type
D) Kit Kat type

... Answer is A)
Explanation will provide as soon as possible.

70. What is the factor of safety used for current ratings in a power installation ?

A) 1
B) 1.5
C) 1.75
D) 2

... Answer is D)
Explanation will provide as soon as possible.

71. Which among these is a method of wiring ?
1-Joint box
2-Tee system
3-Loop in system

A) Only 1
B) Only 2
C) Only 1 and 2
D) 1,2 and 3

... Answer is D)
Explanation will provide as soon as possible.

72. Which among these is a part of distribution system ?
1-Feeders
2-Distributors
3-Service Mains

A) Only 1
B) only 2
C) Only 3
D) 1,2 and 3

... Answer is D)
Explanation will provide as soon as possible.

73. What is the maximum span upto which the wooden poles can be used ?

A) 100m
B) 60m
C) 50m
D) 20m

... Answer is B)
Explanation will provide as soon as possible.

74. For what voltage is the H–type of poles used ?

A) 11 kV
B) 22 kV
C) 130 kV
D) All options are correct

... Answer is C)
Explanation will provide as soon as possible.

75. To prevent the decaying owing to snow and rain, the wooden poles are protected by .... cap at the top. ?
1-Aluminimum
2-Zinc
3-Cement

A) Only 1
B) Only 2
C) Only 3
D) 1,2 and 3

... Answer is D)
Explanation will provide as soon as possible.

76. Steel rail poles of height 13 meters are used for transmission purpose of ?

A) 11kV
B) 22kV
C) 33kV
D) Both 33 kV and 11 kV

... Answer is C)
Explanation will provide as soon as possible.

77. The squirrel–cage winding of a single–phase motor is placed in the ?

A) Armature
B) Rotor
C) Stator
D) Field

... Answer is B)
Explanation will provide as soon as possible.

78. NEMA standards rate motors according to ?

A) Frame number
B) Horsepower
C) Voltage
D) Weight

... Answer is A)
Explanation will provide as soon as possible.

79. Which of the following motors is most suitable for signaling devices and timer ?

A) D.C. series motor
B) D.C. shunt motor
C) Two phase induction motor
D) Reluctance motor

... Answer is D)
Explanation will provide as soon as possible.

80. The purpose of skewing of rotor slots in induction motor is ?

A) To reduce the magnetic hum of the motor
B) To increase the distribution factor
C) To reduce the locking tendency of rotor
D) To increase the breadth factor

... Answer is C)
Explanation will provide as soon as possible.

81. In an induction motor if the rotor resistance is equal to stand–still reactance then the maximum torque is ?

A) Less than starting torque
B) Equal to starting torque
C) More than starting torque
D) None of these

... Answer is B)
Explanation will provide as soon as possible.

82. The m.m.f produced by a single phase winding is ?

A) Pulsating and stationary
B) Pulsating and rotating
C) Constant in amplitude and stationary
D) Constant in amplitude and rotating

... Answer is A)
Explanation will provide as soon as possible.

83. Usually wide and very sensitive speed control is require in case of ?

A) Reciprocating pumps
B) Colliery winders
C) Centrifugal blowers
D) Lathe machines

... Answer is B)
Explanation will provide as soon as possible.

84. Inter–poles are used in ?

A) Lap wound machines
B) Wave wound machines
C) Both lap and wave wound machines
D) None of these

... Answer is C)
Explanation will provide as soon as possible.

85. For the production of induced e.m.f field system of an electric machine ?

A) Must be on stator
B) Must be on rotor
C) May be on stator or rotor
D) None of these

... Answer is C)
Explanation will provide as soon as possible.

86. The number of conductors of the compensating winding in a D.C. machine ?

A) is always more than the number of armature conductors per pole
B) Is always less than the number of armature conductors per pole
C) May be less or more than the number of armature conductors per pole
D) None of these

... Answer is B)
Explanation will provide as soon as possible.

87. Two D.C. machines 500 kW each are tested by Hopkinson testing method. The power input would be oes 500 kW ?

A) 100kW
B) 500kW
C) 1000kW
D) None of these

... Answer is C)
Explanation will provide as soon as possible.

88. In a D.C. machine, how are the commutating pole winding connected ?

A) In series with the armature winding
B) In series with the shunt winding
C) Parallel to the shunt winding
D) Parallel to the armature winding

... Answer is A)
Explanation will provide as soon as possible.

89. In motor circuit static frequency changers are used for ?

A) Improved cooling
B) Power factor improvement
C) Reversal of direction
D) Speed regulation

... Answer is D)
Explanation will provide as soon as possible.

90. In case of traveling cranes, the motor preferred for boom hoist is ?

A) Slip ring induction motor
B) Single phase motor
C) Squirrel cage induction motor
D) Synchronous motor

... Answer is A)
Explanation will provide as soon as possible.

91. Light duty cranes are generally used in ?

A) Automobile workshops
B) Power houses
C) Pumping stations
D) All options are correct

... Answer is D)
Explanation will provide as soon as possible.

92. 15 minutes rated motors are suitable for ?

A) Medium duty cranes
B) Light duty cranes
C) Heavy duty cranes
D) All options are correct

... Answer is B)
Explanation will provide as soon as possible.

93. Free running and coasting periods are generally long in case of ?

A) Urban service
B) Sub–urban service
C) Main–line service
D) All options are corrects

... Answer is C)
Explanation will provide as soon as possible.

94. Arc blow is a welding defect which is encountered in ?

A) Arc welding using D.C. current
B) Arc welding using A.C. current
C) Gas welding
D) Thermit welding

... Answer is B)
Explanation will provide as soon as possible.

95. Portion of the installed reserve kept in operable condition but not placed in service to supply the peak load is known as ?

A) Operating reserve
B) Spinning reserve
C) Cold reserve
D) Hot reserve

... Answer is C)
Explanation will provide as soon as possible.

96. The transmission lines which feed different sub–stations represent ?

A) Primary transmission
B) Secondary transmission
C) Primary distribution
D) Secondary distribution

... Answer is C)
Explanation will provide as soon as possible.

97. Transmitting power at high voltage requires more ?

A) Maintenance and protection of the equipment
B) Faster controls for minimising the arcing of contacts
C) Larger controls for minimising the arcing of contacts
D) All options are correct

... Answer is D)
Explanation will provide as soon as possible.

98. Copper conductors are generally used for transmission lines because it ?

A) Has longer life and high conductivity
B) Is strong enough to allow long
C) Requires more support
D) Requires more insulators

... Answer is A)
Explanation will provide as soon as possible.

99. The conductors used for transmitting power must have following characteristics ?

A) It should be light in weight and not brittle
B) It should have low value of specific resistance
C) It should have low cost and high tensile strength
D) All options are correct

... Answer is D)
Explanation will provide as soon as possible.

100. Steel poles are generally used for transmission lines because 1- It has more mechanical strength and more life
2- It occupies less space and give better appearance
3- It has high cost
Which of the above provided reason ?

A) Only 1
B) Only 2
C) Only 3
D) Both A and B

... Answer is D)
Explanation will provide as soon as possible.