SSC junior Engineer Exam 2014 Evening

1. The highest transmission a.c. voltage in India is ?

A) 220 kV
B) 400kV
C) 1750 kV
D) 132kV

... Answer is #)
At present, the highest AC transmission voltage in INDIA is 765 kV, whereas the highest HVDC transmission voltage operating in INDIA is ± 800 kV. It may be noted that in Madhya Pradesh, there is one km transmission line which transmits the power at 1200 kV. However, this line is under testing condition in India. .

2. Three resistors, each of ′R′ Ω are connected in star.What is the value of equivalent delta connected resistors ?

A) 2 R Ω
B) 3R Ω
C) R/3 Ω
D) R/2 Ω

... Answer is B)
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3. After closing the switch ′S′ at = t = 0, the current i (t) at any instant ′t′ in the network shown in the figure: ?

A) 10 – 10 e100 t
B) 10 + 10 e− 100 t
C) 10 – 10 e− 100 t
D) 10 + 10 e100 t

... Answer is C)
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4. Find R3 for the circuit shown in figure: ?

A) 25 ohm
B) 25 kilo ohm
C) 25 mega ohm
D) 25 mili ohm

... Answer is B)
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5. Diversity factor has direct effect on the: ?

A) Variable cost of the unit generated
B) Both variable and fixed cost of unit generated
C) Operating cost of unit
D) Fixed cost of the unit generated

... Answer is D)
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6. Which one of the following bridges is generally used for measurement of frequency and also capacitance ?

A) Owen′s bridge
B) Schering bridge
C) Wien bridge
D) Hay′s bridge

... Answer is C)
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7. A capacitor with no initial charge at t = ∞ acts: ?

A) Current Source
B) Short- Circuits
C) Open – Circuit
D) Voltage Source

... Answer is C)
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8. Consider a constant uniform magnetic field. A conductor moves across this field at a constant velocity.The emf induced in the conductor is termed as ?

A) Statically induced emf
B) Dynamically Induced emf
C) Self – Induced emf
D) Induced emf

... Answer is B)
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9. The mutual inductance between two unity coupled coils of 9H and 4H will be: ?

A) 6 H
B) 13 H
C) 36 H
D) 2.2 H

... Answer is A)
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10. Transient current in RLC circuit is oscillatory when the value of R is ?

A) less than 2 C L
B) more than 2 L C
C) A S
D) M S

... Answer is )
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11. The active and reactive powers of an inductive circuit are 60 W and 80 VAR respectively. The power factor of the circuit is ?

A) 0.6 lag
B) 0.75 lag
C) 0.8 lag
D) 0.5 lag

... Answer is A)
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12. Which of the following condition is NOT mandatory for alternators working in parallel ?

A) The alternators must operate at the same frequency
B) The machines must have equal kVA ratings.
C) The alternators must have the same phase sequence.
D) The terminal voltage of each machine must be the same.

... Answer is B)
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13. As per IE rules the permissible variation of voltage at the consumer end is: ?

A) ± 12%
B) ± 2%
C) ± 6%
D) ± 10%

... Answer is C)
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14. The rated voltage of a 3-phase power system is given as ?

A) peak phase voltage
B) rms line to line voltage
C) peak line to line voltage
D) rms phase voltage

... Answer is B)
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15. Point out of the WRONG statement. The magnetizing force at the centre of a circular coil varies: ?

A) directly as the current
B) directly as its radius
C) inversely as its radius
D) directly as the number of its turns

... Answer is B)
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16. Which of the following motor will give relatively high starting torque ?

A) Capacitor run motor
B) Split phase motor
C) Shaded pole motor
D) Capacitor start motor

... Answer is D)
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17. Using Millman′s theorem, find the current through the load resistance RL of 3 Ω resistance shown below: ?

A) 6 A
B) 8 A
C) 12 A
D) 4 A

... Answer is D)
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18. The energy stored in the magnetic field of a solenoid 30cm long and 3cm diameter with 1,000 turns of wire carrying current of 10A is ?

A) 0.15 J
B) 0.5 J
C) 1.15 J
D) 0.015 J

... Answer is A)
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19. A magnet is kept in medium of air surrounded by an iron ring. The magnetic lines of force from the magnet will be ?

A) Evenly distributed within the ring
B) Passing out of the ring
C) Crowded in ring
D) Very small in ring

... Answer is C)
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20. To increase the range of an a.c. ammeter you would use ?

A) A potential transformer
B) An inductance across the meter
C) A condenser across the meter
D) Current transformer

... Answer is D)
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21. The magnetic potential difference in a magnetic circuit is given by: ?

A) B l
B) H l
C) B / H
D) H J l

... Answer is B)
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22. A delta – star transformer has a phase to phase voltage transformation ratio of a :1 [delta phase: star phase]. The line to line voltage ratio of star-delta is ginven by: ?

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

... Answer is A)
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23. The magnetic field energy in an inductor changes from maximum value to minimum value in 5 m sec when connected to an a.c. source. The frequency of the source is: ?

A) 50 Hz
B) 200 Hz
C) 500 Hz
D) 20 Hz

... Answer is A)
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24. If a 10- µF capacitor is connected to a voltage source with v(t) = 50 sin 2000 t V, then the current through the capacitor is ----- ?

A) cos 2000 t
B) 500 cos 2000 t
C) 106 cos 2000 t
D) 5 × 10−4 cos 2000 t

... Answer is A)
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25. Moving coil (PMMC) and moving iron instruments can be distinguished by observeing its ?

A) range
B) scale
C) size of terminals
D) pointer

... Answer is B)
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26. Quadrilateral speed time curve is used for ?

A) urban service
B) main line service
C) goods line service
D) sub urban service

... Answer is A)
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27. Find the current through 5 Ω resistor: ?

A) 5 A
B) 2.85 A
C) 3.5 A
D) 7.15 A

... Answer is B)
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28. Hydrogen is used in large alternators mainly to ?

A) cool the machine
B) strengthen the magnetic field
C) reduce eddy current losses
D) reduce distortion of wave form

... Answer is A)
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29. A 150 V.d.c. motor of armature resistance 0.4 Ω has back emf of 142 V. The armature current is ?

A) 10 A
B) 150 A
C) 100 A
D) 20 A

... Answer is D)
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30. The synchronous speed of a three phase induction motor having 20 pole and connected to a 50 Hz source is: ?

A) 600 rpm
B) 1000 rpm
C) 1200 rpm
D) 300 rmp

... Answer is D)
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31. In a 3 1 2 digit voltemeter, the largest number that can be read is ?

A) 1999
B) 5999
C) 9999
D) 0999

... Answer is A)
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32. A generating station supplies the following loads 15000 kW. 12000 kW, 8500 kW, 6000 kW and 450 kW. The station has maximum demand of 22000 kW. Calculate the diversity factor. ?

A) 0.68
B) 1.34
C) 1.91
D) 0.52

... Answer is C)
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33. Determine the voltage at point C shown below with respect ground: ?

A) 40 V
B) 70 V
C) 80 V
D) 120 V

... Answer is A)
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34. "Danger 440 V " plates are: ?

A) danger notices
B) advisory notices
C) caution notices
D) information notices

... Answer is C)
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35. A terminal where three or more branches meet is know as ?

A) terminus
B) loop
C) mesh
D) node

... Answer is A)
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36. which of the following is non- linear circuit parameter ?

A) Condenser
B) Wire wound resistor
C) Transistor
D) Inductance

... Answer is C)
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37. The power factor of an a.c. circuit is given by ?

A) R/Z
B) R/XL
C) Z/R
D) XL/R

... Answer is A)
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38. As compared to full - wave rectifier using two diodes, the four diode bridge rectifier has the dominant advantage of: ?

A) lower peak inverse voltage requirment
B) lower ripple factor
C) higher efficiency
D) higher current carrying capacity

... Answer is A)
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39. For average values of load current, current chopping occurs more freqently in: ?

A) ACB'S
B) SF6 CB'S
C) VCB'S
D) OCB'S

... Answer is C)
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40. Welding is injurious to eye because of: ?

A) infrared radiation
B) ultraviolet radiation
C) both (A) and (B) are wrong
D) both (A) and (B) are correct

... Answer is A)
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41. The type of protection that does not respond to faults occurring beyond its zone even though the fault current may pass through the zone is ?

A) Unit protection
B) Generator protection
C) Back - up protection
D) Busbar protection

... Answer is A)
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42. Bundled conductors in EHV transmission system provide ?

A) reduced line capacitance
B) reduced voltage gradient
C) increased line reactane
D) increased corona loss

... Answer is B)
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43. The rated speed of a given d.c. shunt motor is 1050 r.p.m. To run this machine at 1200 r.p.m the following speed control scheme will be used ?

A) Field resistance control
B) Ward - Leonard control
C) Armature circuit resistance control
D) Varying frequency

... Answer is A)
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44. A magnetic circuit carries a flux φi in the iron part and a flux φg in the air gap. Then leakage co-efficient is ?

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

... Answer is A)
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45. The efficiency normally obtained in circuit under the conditions of maximum power transfer is ?

A) 75%
B) 50%
C) 100%
D) 25%

... Answer is B)
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46. The least number of 1 - φ wattmeters required to measure total power consumed by an unbalanced load fed from a 3φ,n 4 wire system is: ?

A) 1
B) 2
C) 3
D) 4

... Answer is C)
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47. In a fluorescent tube circuit, the function of choke is primarily to: ?

A) reduce the flicker
B) reduce the starting current
C) improve the brightness of the tube
D) initiate the discharge

... Answer is D)
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48. In a series resonance circuit, the impedance at half power frequencies is ?

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

... Answer is A)
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49. What is the order of minimum displacement that can be measured with capacitive transducers ?

A) 1 µ m
B) 1 mm
C) 1×10−12m
D) 1cm

... Answer is A)
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50. Total capacitance between the points L and M in figure is: ?

A) 1.85 µ F
B) 2.05 µ F
C) 4.05 µ F
D) 1.45 µ F

... Answer is B)
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51. The Ebers- Moll model is applicable to: Syej- ceesue cee@[ue efkeâme hej ueeiet neslee nw ?

A) NMOS transistor
B) UJT
C) JFET
D) BJT

... Answer is D)
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52. An ideal voltage source should have: ?

A) small value of emf
B) zero source resistance
C) infinite source resistance
D) large value of emf

... Answer is B)
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53. For a half wave rectified sine wave the ripple actor is: ?

A) 1.45
B) 1.00
C) 1.21
D) 1.65

... Answer is C)
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54. Two d.c. series motors connected in series draw current I from supply and run at speed N. When the same two motors are connected in parallel taking current I from the supply, the speed of each motor will be ?

A) 2 N
B) 4 N
C) N / 2
D) N

... Answer is B)
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55. Which of the following motor has high starting torque ?

A) d.c. series motor
B) induction motor
C) synchronous motor
D) a.c. series motor

... Answer is A)
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56. The distribution losses that the utility suffers while transferring power from generating station to the consumer is accounted under ?

A) Running Charges
B) Cost of fuel
C) Maintenance cost
D) Fixed charges

... Answer is A)
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57. In power plant if the maximum demand on the plant is equal to the plant capacity, then ?

A) diversity factor will be unity
B) load factor will be unity
C) load factor will be nearly 60%
D) plant reserve capacity will be zero

... Answer is D)
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58. The voltage across ?

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

... Answer is A)
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59. Two wires A and B have the same cross section and are made of the same material. RA = 800 Ω and RB = 100. The number of times A is longer than B is ?

A) 2
B) 4
C) 5
D) 6

... Answer is D)
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60. A d.c. voltmeter has a sensitivity of 1000 Ω/ watt. When it measure half full scale in 100 V range, the current through the voltmeter will be ?

A) 1mA
B) 0.5 mA
C) 50 mA
D) 100 mA

... Answer is C)
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61. Two electric bulbs have tungsten filament of same thickness. If one of them give 60 W and the other gives 100 W, then: ?

A) 100 W lamp filament has longer length
B) 60 W lamp filament has longer length
C) 60 W and 100 W lamp filaments have equal length
D) 60 W lamp filament has shorter length

... Answer is B)
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62. Which of the following motors can be run on A.C. as well as D.C. supply ?

A) Repulsion motor
B) synchronous motor
C) Reluctance motor
D) universal motor

... Answer is D)
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63. Super position theorem can be applied only to: ?

A) non-linear networks
B) linear bilateral networks
C) bilateral network
D) linear networks

... Answer is B)
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64. A 10Ω resistive load is to be impedance matched by a transformer to a source with 6250 Ω of internal resistance. The ratio of primary to secondary turns of transformer should be ?

A) 10
B) 15
C) 20
D) 25

... Answer is D)
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65. If F is the load factor, the loss load factor is given by: ?

A) 0.25 F2 + 0.85 F
B) 0.75 F + 0.20 F2
C) 0.35 F + 0.7 F2
D) 0.25 F + 0.75 F2

... Answer is D)
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66. An isolator is used in series with Air blast Circuit Breaker employed at UHV lines because: ?

A) gap between CB contacts is small so an isolator is used to switch off voltage
B) gap between CB poles the use of isolator
C) CB life is enhanced with the use of isolator
D) current to be interrupted will be large

... Answer is A)
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67. If resistance is 20Ω and inductance is 2 H in a RL series circuit, then time constant of this circuit will be ?

A) 0.1s
B) 10s
C) 0.001s
D) 100s

... Answer is A)
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68. For V- curves for a synchronous motors the graph is drawn between: ?

A) terminal voltage and load factor
B) power factor and field current
C) armature current and power factor
D) field current and armature current

... Answer is D)
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69. The positive, negative and zero sequence impedances of 3-phase synchronous generator are j 0.5 pu, j 0.3 pu and j 0.2 pu respectively. When symmetrical fault occurs on the machine terminals. Find the fault current. The generator neutral is grounded through reactance of j.01 pu. ?

A) - j 2.0 pu
B) - j 2.5 pu
C) - j 3.33 pu
D) - j 1.67 pu

... Answer is D)
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70. A lamp having mean spherical candle power of 800 is suspended at a height of 10 m. Calculate the illumination just below the lamp. ?

A) 80 lux
B) 800 lux
C) 8000 lux
D) 8 lux

... Answer is D)
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71. In suburban services as compared with urban service ?

A) the coasting period is longer
B) the coasting period and free running periods are same
C) the coasting period is smaller but free running period is longer
D) the coasting period is smaller

... Answer is A)
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72. Thevenin's equivalent voltage and resistance between the terminal A and B for network of given figure is ?

A) 12.5 V, 3.75Ω
B) 12.5 V, 2.5Ω
C) 2.5 V, 12.5 Ω
D) 2.5 V,3.75Ω

... Answer is A)
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73. Speed of the megger is kept at ?

A) 120 rpm
B) 140 rpm
C) 160 rpm
D) 100 rpm

... Answer is C)
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74. The power factor of the circuit show in figure ?

A) 0.3 lagging
B) 0.8 lagging
C) 0.75 lagging
D) 0.6 lagging

... Answer is B)
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75. The speed of a p-pole synchronous machine in r.p.m. is givin by: ?

A) 120 p f
B) 120 f p
C) 120 f p
D) 120 f p

... Answer is D)
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76. The Biot-Savart's law is a general modification of ?

A) Lenz's law
B) Ampere's law
C) Faraday's law
D) Kirchhoff's law

... Answer is B)
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77. In which single - phase motor, the rotor has no teeth or winding ?

A) Reluctance motor
B) Hysteresis motor
C) Universal motor
D) Split phase motor

... Answer is B)
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78. The rotor slots, in an induction motor are usually not quite parallel to the shaft because it ?

A) helps the rotor teeth to remain under the stator
B) helps in reducing the tendency of the rotor
C) improves the power factor
D) improves the efficiency

... Answer is B)
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79. Low frequency operation of a.c. series motor in traction application ?

A) Improve its commutation, pf and efficiency
B) Adversely affects commutation but pf and n improves
C) Improves its commutation but starting current increases
D) Improves its commutation property but pf and n reduces.

... Answer is A)
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80. When the rotor of a three phase induction motor is blocked, the slip is: ?

A) 0.1
B) 0.5
C) 1
D) 0

... Answer is C)
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81. Two voltmeters of (0-300V) range are connected in parallel to a a.c. circuit. One voltmeter is moving iron type reads 200 V. If the other is PMMC instrument, its reading will be: ?

A) zero
B) 222 V
C) 127.4 V
D) slightly less 200 V

... Answer is A)
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82. EMF induced in a coil rotating in a uniform Magnetic field will be maximum when the ?

A) Rate of change of flux linkage is minimum
B) Rate of change of flux linkage is maximum
C) Rate of cutting flux by the coil sides is minimum.
D) Flux linking with the coil is maximum

... Answer is B)
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83. Regulation of an alternator supplying resistive or inductive load is: ?

A) always positive
B) zero
C) infinity
D) always negative

... Answer is A)
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84. The current in reverse bias in P-N junction diode may be: ?

A) few mili amperes
B) between 0.2 A and 2A
C) between 2 A and 5A
D)few micro or nano amperes

... Answer is D)
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85. The maximum demand of a consumer is 2 kW and his daily energy consumption is 20 units. His load factor is ?

A) 41.6%
B) 50%
C) 21%
D) 10.15%

... Answer is A)
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86. A BJT is said to be operating in the saturation region, if: ?

A) B-E junction is reverse biased and B-C junction is forward biased.
B) B-E junction is forward biased and B-C junction is reverse biased.
C) Both the junctions are forward biased
D) Both the junctions are reverse biased

... Answer is C)
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87. A 2 cm long coil has 10 turns and carries a current of 750 mA. The magenetising force of the coil is ?

A) 675 AT /m
B) 450 AT/ m
C) 375 AT/ m
D) 225 AT/ m

... Answer is C)
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88. In the circuit shown in figure, find the transient current i(t) when the swith is closed at t = 0, Assume zero initial condition. ?

A) 100 t e-5t
B) 100 t e- 0.5t
C) 50 t e- 0.5t
D) 50 t e-5t

... Answer is A)
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89. Which semiconductor device behaves like two SCR's ?

A) JFET
B) UJT
C) Triac
D) MOSFET

... Answer is C)
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90. The repulsion -start indunction- run motor is used because of ?

A) high efficiency
B) minimum cost
C) high starting torque
D) good power factor

... Answer is C)
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91. A circuit with a resistor, inductor and capacitor in series is resonant of f0Hz. If all the component values are now doubled the new resonant frequency is ?

A) f0
B) f0 /2
C) f0 /4
D) 2 f0

... Answer is B)
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92. A consumer has annual consumption of 7,00,800 unit. If his maximum demand is 200 kW. The load factor will be ?

A) 20%
B) 50%
C) 40%
D) 70%

... Answer is C)
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93. The purpose of choke in a fluorescent tube is to ?

A) increase current
B) decrease voltage momentarily
C) increase voltage momentarily
D) decrease current

... Answer is C)
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94. The B-H curve is used to find the mmf of this section of the magnetic circuit. The section is: ?

A) air gap
B) both iron part and air gap
C) vacuum
D) iron part

... Answer is D)
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95. A synchronous motor working at leading power factor can be used as ?

A) phase advancer
B) noise generator
C) mechanical synchronizer
D) voltage booster

... Answer is A)
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96. A3 phase 4 pole induction motor works on 3- phase 50 c/s supply. If the slip of the motor is 4%. The actual speed will be ?

A) 1460 rpm
B) 1440 rpm
C) 720 rpm
D) 1550 rpm

... Answer is B)
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97. For which of the following the excitation control method is satisfactory ?

A) High voltage lines
B) Short line
C) Long line
D) Low voltage line

... Answer is B)
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98. A wheat stone bridge has ratio arm of 1000 Ω and 100 Ω resistances, the standard resistance arm consist of 4 decade resistance boxes of 1000,100,10,1 Ω steps. The maximum and minimum value of unknown resistance that can be determined with this setup are ?

A) 11110 Ω ,10Ω
B) 10000 Ω, 10Ω
C) 111100 Ω, 10Ω
D) 111100 Ω, 1Ω

... Answer is C)
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99. Two 100 W, 200 V lamps are connected in series cross a 200 V supply. The total power consumed y each lamp will be watts ?

A) 50
B) 100
C) 200
D) 25

... Answer is D)
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100. The least expensive fractional horse power motor is ---motor ?

A) capacitor start
B) split phase
C) A.C. series
D) shaded pole

... Answer is D)
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