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EXAM DURATION: 3 hours only 9.

A transmission line of 210 km length has certain

values of A, B, C and D constants. If the length of the
1. A 240-V, 60 cycle source is connected to a coil of line is made 100 km, then the parameter____.
wire that has a resistance of 7.5 ohms and an A. A increases and B decreases
inductance of 0.0477 H. Solve the real power drawn. B. A and B both increases
A. 1138 W B. 1052 W C. 1202 W D. 1216 W C. A and B both decreases
D. A decreases and B increases
2. The power output of a cellular radio is controlled
by the 10. A delta-delta power transformer is protected by
A. user or caller CT having____connections.
B. cell site A. star/star
C. called party B. star/delta
D. MTSO C. delta/delta
D. delta/star
3. A series RL circuit with R= 100 ohms; L =50 H, is
supplied to a dc source of 100 V. The time taken for 11. In a thermal power plant a cooling tower
the current to rise 70% of its steady-state value is cools____.
A.0.3s B. 0.6s C. 2.4 s D. 0.45s A. steam from boiler
B. Water from economizer
4. Device number of undervoltage relay is C. Steam from turbine
A. 27 D. Water from condenser.
C. 67 12. A balanced 3-phase system consists of
D. 40 A. zero sequence currents only
B. positive sequence currents only
5. A 300 km long overhead line has a surge C. negative and zero sequence currents only.
impedance of 400 ohms. For 600 km length, the D. zero, negative and positive sequence currents
surge impedance will be
A. 100 ohms 13. Two coupled coils connected in series have an
B. 400 ohms equivalent inductance of 16 mH or 8 mH depending
C. 200 ohms on the interconnection. Then the mutual inductance
D 800 ohms between the coils is
A. 12 mH
6. A dc line carries____an equivalent ac line. B. 4 mH
A. less power than C. 8 mH
B. equal power as D. 2 mH
C.more power than
D.none of these 14. Which of the following equipment is installed in
steam power plants to reduce air pollution?
7. A 600 kVA, single-phase transformer when A. Desuper heater
working at unity power factor has an efficiency of 92 B. Stock
% at full load and also at half load. What will be the C. Air filter
efficiency whén the transformer operates at unity pf D. Electrostatic precipitator
and 60% of full load?
A. 94.2% B. 92.3% C. 93.5 % D. 91.8%

8. Which of the following plants is almost inevitably

used as base load plants? 15. The currents flowing in L and C at parallel
A. Diesel engine plants resonance are
B. Pumped storage plants A. zero
C. Gas turbine plants C.equal
D. Nuclear power plants D.different
B. infinite
16. If the secondary terminals of a 5:1 step down D. 225 W
transformer is connected to the primary of a 2:1
step down transformer then the total step down
ratio of both transformer is 23. Fault calculation that uses positive and negative
A. 5:2 sequence impedance only.
B. 100: 1 A. Line to line fault
C. 10: 1 B. Three-phase fault
D. 25: 42 C. Single-line to ground fault
D. Double-line to ground fault
17. A zigzag transformer is used as
A. a potential transformer 24. In the transformer the function of a conservator
B. an isolation transformer is to
C. a grounding transformer A. provide fresh air for cooling the transformer
D. a booster transformer B. supply, cooling oil to transformer in time of need
C. to prevent explosion due to rise in oil pressure
18. An electrical system experience linear changes inside the tank during a fault
in load such that the daily load curve is defined as D. protect the transformer from damage when oil
follows: 12 PM, 24 MW; 2 AM, 12 MW; 6 AM, 12 expands due to heating
MW; 8 AM, 60 MW; 12 AM, 60 MW; 12:30 PM, 48
MW; 1 PM, 60 MW; 5 PM, 60 MW; 6 PM, 84 MW 25. Which of the following medium is employed for
and 12 PM, extinction of arc in air circuit breaker?
24 MW. Find the load factor. A. Oil
A. 53.86% B. Vacuum
B.42.93% C SF6
C. 48.28% D. Air
D. 57.18%
26. A short three-phase line connected to a 33 kV
19. In semi-conductors, a donor type impurity must generating station at the sending end is to supply a
have load of 1O MW at 0.8 pf lagging at 30 kV at the
A. no charge receiving end. If the minimum transmission
B. negative or positive charge efficiency is to be 0.96, determine the resistance per
C. only three valence electrons phase of the line.
D. only five valence electrons A. 2.2 ohms
B. 1.2 ohms
20. Which alternator usually runs at slow speed as C. 1.8 ohms
compared to others? D. 2.4 ohms
A. coupled to gas turbine
B Coupled to hydraulic turbine 27. The process of deliberately adding impurity to a
C. Coupled to steam turbine semi-conductor material is called
D. Coupled to diesel engine A. Ionization
C. Bonding
21. Wooden poles for supporting transmission lines D. Doping
are used for voltages up to B. Diffusing
A. 1440 V
B. 22 kV 28. Where does a fluorescent lamp cannot be
C. 11 kV mounted that easily causes fire?
D. 66 kV A. Dry wall or plaster
B. Framing member
22. A 125-V, 25-Hz source is connected to a series C. Concrete
circuit consisting of a 30 ohm resistor and a 159-uF D. Cellulose fiber
capacitor. Determine the power taken by the circuit.
A. 154 W 29. Which of the following is not considered in
B. 206 W selection of surge arrester?
C. 188 W A. Voltage rating
B. Insulation level D. reflector
C. Class
D. Current rating 37. A transformer rated at a maximum of 25 kVA
supplies a 12 kW load at a power factor 0.60 lagging
30. Which factor is least important for base load How many kW in additional load maybe added at
plant unity pOwer factor before the transformernexceeds
A. High efficiency its rated kVA?
B. High availability A. 6.5 kW
C.Quick starting B. 7.2 kW
D. Low capital cost C. 5.8 kW
D. 8.3 kW
31. Load curve of a power plant has always
A. zero slopes 38. Distance relay is device number
B. positive slopes A. 76
C. negative slopes C. 79
D. any combination of A, B and C D 30
B. 21
32 . An alternator of 300 kW is driven by a prime
mover of speed regulation 4% and another 39 For reducing tower footing resistance, it is better
alternator of 200 kW driven by a prime mover of to use _____.
speed regulation 3 % , the total load they can A. chemical and ground rods only
take is B. chemical and counterpoise only
A. 435 kW C. ground rods and counterpoise only
B. 445 kW D. chemical, ground rods and counterpoise
C. 425 kW it is better to use
D. 455 kW
40. Which of the following is usually not a
33. Printed documents to be transmitted by fax are generating voltage?
converted into baseband electrical signal by the A. 6.6 kV
process of B. 11 kV
A. reflection D. 13.2 kV
B. scanning C. 9.9 kV
C. modulation 41. The exact natural frequency of free oscillatory
D. light variation circuit with capacitance of 0.055 uF, inductance 2
uH and resistance 1 ohm will be
34. A power system network with a capacity of 100 A. 479 kHz
MVA has a B. 272 kHz
source impedance of 10 % at a point. The fault level C. 337 kHz
at that point D. 192 kHz
A. 10 MVA
B. 333.33 MVA 42. An unconventional conductor consists of three
C. 17.32 MVA strands arranged vertically. Find the GMR in terms
D. 1000 MVA of the radius r of an individual strand.
A. 1.864r
35. A tap changing transformer is used to B. 1.524r
A. supply low voltage current for instruments C. 1.764r
B. step up the voltage D. 1.704r
C. step down the voltage
D. step up as well as step down the voltage 43. Most fiber optic light sources emit light in which
36. Basically a lightning arrester is a surge A. Visible
A. diverter B. Ultraviolet
B. generator C. Infrared
C. absorber D. X-ray
kph, how much power is obtainable from the
44. A three-phase short transmission line is 16 km generator?
long. The line has a per phase series impedance of A. 58 kW
0,125 +i0.4375 ohm per km. Determine the sending- B. 60 kW
end line voltage when the line delivers 120 MW, C. 56 kW
unity power factor at 64 kV. D. 62 kW
A. 69 kV
B. 68 kV 51. Regulation is considered In designing the
C. 66 kV following except in
D. 67 kV A.transmission line
B.bus bar
45. In hydroelectric plant a conduct system for C. generator
taking water from the intake works to the turbine is D. transformer
known as
A. reservoir 52. A volume of 1,000,000 m of water is stored in a
B. penstock reservoir feeding a water turbine If the center of
C. forebay mass of mass of the water Is 50m above the turbine
D. surge tank and losses are-negligible, how much energy in MWh
will the yolume of water produce? Assume the
46. Two wye-connected identical, synchronous density of water Is 993 kg/m
generators operating in parallel, share equally a 1- A. 135
MW load at 11 kV and 0.8 lagging B. 203
power factor. If one machines supplies 40 A at a C. 187
lagging power factor. Determine the power factor of D. 128
the second machine.
A.0.91 lag C. 0.92 lag 53. Which one is not a part of a transformer?
B. 0.93 lag D. 0.94 lag A. Radiator
47. Generating capacity connected to the bus bars B. Bushing
and ready to take load when switched on is known C. Load tap changer
as D. Oil drum
A. firm power
B. hot reserve 54. A 6 V car radio draws a current of 6.5 A. What
C. cold reserve resistance in ohms must be connected in series with
D. spinning reserve It to operate It In a car with a 12 V battery?
A. 1.846 ohms
48. An energy meter whose constant is 600 B. 0.923 ohms
revolutions per kWh, makes 5 revolutions in 20 s. C. 0.846 ohms
Calculate the load in kW. D. 2.769 ohms
A. 2.2 kW
B. 1.8 kW 55. The ratio of the readings of two wattmeters
C. 1.5 kW connected to measure power in a balanced 3-phase
D. 1.2 kW load is 5:3 and the load is inductive. The power
factor of the load is
49. A 10 km long, 3-phase line delivers 1 MW at 0.8 A. 0.917 lead
pf lagging The series impedance of the line is B. 0.6 lead
0.5+j0.56, ohm per km per phase. The sending end C. 0.917 lag
voltage is 11 kV. Find the receiving end line voltage. D. 0.6 lag
A. 10.31 kV
B. 10.17 kV 56. The secondary line voltage will be least for
C. 10.09 kV which of the following connections?
D. 10.21 kV A. Delta-delta
B. Delta-star
50. A wind generator with an efficiency of .85 has a C. Star-star
blade diameter of 20 m. If the wind velocity is 30 D) Star-delta
64. A 400-V-dc shunt motor take 5 A at no load Ra=
57. The function of the breather in a transformer is 0.5 ohms and Rsh=200 ohms. What is the ratio of
A. to suppress harmonics speed from full load to no-load when the dc shunt
B. to control the level of oil in the tank motor takes 50 A on full load?
C. to arrest flow of moisture into the tank A. 0.69
D. to provide protection against over current B. 0.83
C. 0.94
58. In the EPIRA law, it is an energy loss due to D. 0.72
conductor loss transformer core loss and technical
error in meters.
A. Technical loss 65. A certain amount of fuel can be converted into
B. Power loss O.003 quads of energy in a power station. If the
C. Administrative loss average load on the station over a 24-hour period is
D. Non-technical loss 50 MW, determine how many days the fuel will last.
Assume 20% overall efficiency for the power
59. A piece of conductor 10 cm long moves across a station.
magnetic field of 10,000 G at a velocity of 1.2 m/s. A. 140 days C. 147 days
What voltage appears across the conductor? B. 154 days
A. 1.2 V
B. 0.24 V D. 200 days
C. 2.4 V
D. 0.12 V 66. The secondary winding of which transformers is
always kept closed?
60. A transformer conservator consists of A. Grounding transformer
A. a drum placed at the bottom of the tank B. Potential transformer
B. an air-tight metal drum fixed at the top of the C . Autotransformer
tank D. Current transformer
C. an overload protective devices
D. a high tension insulators 67. Fault calculation that uses positive sequence
Impedances only
61. Direct conversion of heat into electric power is A. Line to line fault
possible through B. Double-line to ground fault
A fuel cells C. Single-line to ground fault
B thermionic converter D. Three-phase fault
C. batteries
D. all of these 68. An 8-pole alternator has 48 slots, and a coil span
is 5 in slots.
62. An 8-pole, three-phase 50-cycle induction motor Calculate the coil span factor.
is taking 50 kW and running at 725 rpm. The stator A.0.9396
losses and frictional losses amount to 1.2 kW and B 0.9659
1.8 kw. Determine motor bhp. D. 0.9781
A. 68 hp C. 0.9510
B. 65 hp
C. 61 hp 69. When the signal from a mobile cellular unit
D. 63 hp drops below a
certain level what action oCcurs?
63. Back to back HVDE is used to A. The unit is handed off to closer cell
B. The call is terminated
A increase the transmission capability C The MTSO increases power level
B. decrease line losses D. The cell site switches antennas
C. reduce voltage drop
D. provide stable interconnection 70. What PEC rule, for disconnecting means shall be
located in sight
from the controller location?
A Manufacturing rule the rotor. The stator frequency is 50 Hz. The slip of
B Installation rule the motor is
C.Wiring rule A. 2%
D. Construction rule C. 4.167%
D. 4%
71. If transformer frequency is change from 50 Hz to B. 5%
60.Hz, the ratio of the eddy current loss at 50 Hz to
60 Hz at constant voltage is 78. Which of the following is not required in a
A. 5/6 typical electrical
B. 6/5 design?
C. 25/36 A. feeder
D. 1.0 B. main disconnecting means
C.overcurrent protection for conductors
72. When a line to ground fault occurs, the current D. the service
in the faulted
phase is 100 A. The zer0 sequence current in this 79. The charging reactance of 50 km line is 1500
case will be ohms, The charging reactance for 100 km length of
A zero line will be
B. 66.6 A C. 3000 ohms
C. 100 A B. 750 ohms
D. 33.3 A A. 1500 ohms
D. 600 ohms
73. The main advantage-of ac transmission.system 80. The steel used in steel-cored conductors is
over dc transmission system is usually
A .easy transformation A. alloy steel
C. less insulation problems B. high speed steel
D. less problem of instability C. stainless steel
B. less losses in transmission over long distances D. mild steel

74. The capacitance of a 3-core cable between any 81. A voltage of 1000 kV is applied to an overhead
two conductors with sheath earthed is 2 uF. The line with its receiving-end open. If the surge
capacitance per phase will be impedance of the line is 500 ohms, then the total
A. 1 μF surge power in the line is
B. 0.667 μF A: 2000 MW
C. 4 μF B. 2 MW
D. 1.414 uF C. 500 MW
D. 0.5 MW
75. For economy in generation power
A, diversity factor should be high 82. Load flow study is carried out for
B. plant utilization factor should be high A. fault calculations
C. load factor should be high B. system planning
D. load factor and diversity factor should be low C. stability studies
D. load frequency controlled
76, A 100 V/10 V, 50 VA transformer is converted to
100 V/110 V autotransformer, the rating of the 83. The positive sequence impedance of a
autotransformer is transmission line
A. 500 VA A. three times the negative sequence impedance
C 550 VA B equal to the negative sequence impedance
B. 110 VA C. one-third of the negative sequence impedance
D. 150 VA D. always zero

77. A voltmeter gives 120 oscillations per minute 84 A balanced three-phase, 3-wire supply feeds
when connected to balance star connected resistors. If one of the
resistors is disconnected, then percentage reduction D. I, II and II
in load will be
A 33 1/3
B. 66 2/3
C. 50 91. What is the main advantage of FMover AM?
D. 75 A. Greater efficiency
B. Capture effect
85. The insulation resistance of a cable of length C. Wider bandwidth
10km is 1 Mohm, its resistance for 50 km length will D. Lower complexity and cost
A. 0.2 Mohms 92. A balanced delta connected load draws 10 A.of
B.0.04 Mohms line current and 3 kW at 220 V. Determine the value
C. 5 Mohms of the reactance of each phase of the load.
D. 1 Mohms A. 30 ohms
B. 24.3 ohms
86. Zero sequence currents can flow from a line into C. 23.5 ohms
a transformerbank if the windings are in D. 88.1 ohms
A. grounded star/delta
B. star/grounded star 93. A lap wound dc machine has 400 conductors
C delta/star and 8 poles. The voltage induced per conductor is 2
D. delta/delta V. The machine generates a voltage of
A. 100 V
87. Depletion region in a PN junction is due to C 200 V
A. reversed biasing D. 800 V
B. forward biasing B. 400 V
C. an area created by crystal doping
D an area void of current carriers 94. In diesel engine the governor controls
A.fuel pressure
88. The ABCD constants of á lossless three-phase B. fuel temperature
500 kV transmission line are: A D=0.86 + 10, B 0+ C-fuel volume
j130.2 D. fuel flow rate
C= j0.002. Solve the sending-end complex power
when the line delivers 1000 MVA at 0.8 lagging 95. In the analysis of short transmission lines which
power factor at 500 kV of the following is neglected?
A. 820 MW+ j310.3 MVAR A. I^2R losses
B. 800 MW + j305.4 MVAR B. Series impedance
C.800 MW+310.3 MVAR C. Shunt admittance
D. 820 MW + 305.4 MVAR D. Length of the line

89. When an alternator is connected to the infinite 96. The bus bars of each alternators of 15%
bus bar and its excitation is gradually increased, the reactance each, are interconnected through tie-bar
terminal voltage will reactors of 15% each. The equivalent impedance to
A .rise fault current for a 3-phase fault in any alternator
B. remain unaltered bus-bar will be
C. drop A. 75%
D. vary rapidly C. 10%
B. 11.25%
90. Which of the following methods of generating D. 15%
electric power from the sea water is more
advantageous? 97. Which of the following power plants the
I. Ocean currents II. Tidal power III. Wave power availability of power is least reliable?
A. I only A. Wind power plant
B. III only B. Geothermal power plant
C. II only C. Tidal power plant
D. Solar power plant

98. When voltage are high and current to be

interrupted is low, the
circuit breaker preferred is
A. air circuit breaker
B. vacuum circuit breaker
C. oil circuit breaker
D. any of these

99 A three-phase, 4-wire feeder is serving.a 5 hp

(ELC 16.7 A), 208 V three-phase motor and three 2
hp (FLC 24 A), 120 V single-phase motors.
Determine the minimum required feeder ampacity.
A. 46.7 A
B. 110.875 A
C. 94.7 A
D. 50.875 A

100.Whenever the conductors are dead ended or

there is a change in the direction of transmission
lines, the insulators used are of the
A. pin type
B. shackle
C. suspension type
D. strain type