PINOY REE Exam Questions PDF

PINOY REE COMPILED 1000+ EE QUESTIONS FOR REE BOARD EXAM 1. Which of the following materials has nearly zero temperature coefficient of resistance? a. carbon c. copper b. porcelain d. mangarin 2. Which of the following materi...

PINOY REE COMPILED 1000+ EE QUESTIONS FOR REE BOARD EXAM 1. Which of the following materials has nearly zero temperature coefficient of resistance? a. carbon c. copper b. porcelain d. mangarin 2. Which of the following materials has a negative temperature coefficient of resistance? a. brass c. aluminum b. copper d. carbon 3. Which of the following statement is true both for a series and a parallel DC circuit? a. powers are additive b. voltages are additive c. currents are additive d. elements have individual currents 4. The superposition theorem is essentially based on the concept of: a. duality c. reciprocity b. linearity d. non-linearity 5. When current flows in a conductor, heat is produced because: a. heat is directly proportional to the square of the current b. of electronic collision c. of interatomic collision d. of Joule‟s law 6. Ohm‟s law can be applied with certain reservations to: a. rectifying devices c. electrolyses b. semiconductors d. thermionic valves 7. The presence of an electric current is made known by a. flashing c. cracking b. effects produced d. electric shock 8. International ohm is defined in terms of resistance of a. a column of mercury c. a unit length of metal wire b. a cube of carbon d. a cube of copper 9. The capacitance of a capacitor is NOT influenced by a. plate thickness c. plate area b. plate separation d. nature of the dielectric 1 10. A capacitor consists of two a. insulators separated by a dielectric b. conductors separated by an insulator c. ceramic plates and one mica disc d. silver coated insulators 11. Point out the WRONG statement The magnetizing force of the center of a circular coil varies a. directly as the number of its turns b. directly as the current c. directly as its radius d. inversely as its radius 12. Permeability in a magnetic circuit corresponds to _______ in an electric circuit a. conductivity c. conductance b. resistivity d. resistance 13. A material commonly used for shielding or screening magnetism is a. brass c. copper b. aluminum d. soft iron 14. Iron becomes magnetized by induction when it is a. heated b. suspended east and west c. near to one end of a magnet d. treated with some chemicals 15. The relative permeability of paramagnetic substance is a. slightly less than 1 c. slightly greater to 1 b. equal to 1 d. very much greater than 1 16. Which of the following materials does not have permanent magnetic dipole a. paramagnetic c. diamagnetic b. antiferromagnetic d. ferromagnetic 17. Which of the following materials is used for making permanent magnets a. carbon steel b. platinum cobalt c. alnico V d. all three mentioned above 2 18. The direction of induced emf can be found by a. Lenz’s law c. Kirchhoff‟s voltage law b. Fleming‟s right-hand rule d. Laplace‟s law 19. Point out the wrong statement Magnetic leakage is undesirable in electric machines because it a. leads to their increased weight b. increases their cost of manufacture c. produces fringing d. lowers their power efficiency 20. If a current of 5A flowing in a coil of inductance 0.1H is reversed in 10ms, emf induced in it is ________ volt. a. 100 c. 1 b. 50 d. 10,000 21. Permanent magnets are normally made of a. aluminum c. cast iron b. wrought iron d. alnico alloys 22. Those magnetic materials are best suited for making armature and transformer cores which have _______ permeability and _______ hysteresis loss a. low, high c. low, low b. high, low d. low, high 23. Ferrimagnetic materials generally behave as a a. semi-conductor c. insulator b. conductor d. any of a, b, or c 24. Eddy current loss can be minimized by a. decreasing the resistance of magnetic medium b. increasing the resistance of magnetic medium c. decreasing the permeability of magnetic medium d. none of these 25. A collapsing field around a coil a. tends to opposed the decay of coil current b. helps the decay of coil current c. tends to aid current flow reversal d. does not effect the coil current flow 3 26. The capacity of a lead-acid cell does not depend on its a. rate of charge c. temperature b. rate of discharge d. quantity of active material 27. Trickle charging of a storage battery helps to a. prevent sulphation b. keep it fresh and fully charged c. maintain proper electrolyte level d. increase its reserve capacity 28. A dead storage battery can be revived by a. a dose of sulfuric acid b. adding so called battery restorer c. adding distilled water d. none of the above 29. The growth of current in an inductive circuit follows a. hyperbolic law c. exponential law b. ohm‟s law d. linear law 30. It is difficult to magnetize steel because of its a. low permeability c. high permeability b. high retentivity d. high density 31. Hysteresis losses can be reduced by a. Using grain-oriented silicon steel b. Increasing the frequency of the field c. Laminating the core d. None of these 32. The unit of field intensity is a. coulomb c. newtons/coulomb b. coulomb/m2 d. none of the above 33. Dielectric strength of a material depends on a. moisture content c. temperature b. thickness d. all of the above 34. If a dielectric is placed in an electric field, the field strength a. decreases c. remains the same b. increases d. becomes zero 4 35. The KW-hr meter can be classified as a/an _____________ instrument a. deflecting c. recording b. digital d. indicating 36. The moving system of an indicating type of electrical instrument is subjected to a. a deflecting torque c. a damping torque b. a controlling torque d. all of the above 37. The damping force acts on the moving system of an indicating instrument only when it is a. moving c. near its full deflection b. stationary d. just starting to move 38. Which of the following ammeter will be used to measure alternating currents only? a. electrodynamic type c. induction type b. permanent magnet type d. moving-iron 39. The condition of a liquid electrolyte is measured in terms of its a. current value c. acid content b. specific gravity d. voltage output 40. The two main defects of the primary cell are a. polarization and sulphation b. local action and polarization c. buckling and polarization d. sulphation and buckling 41. One advantage of a secondary cells is that it a. can be easily recharged b. can be sued for portable equipment c. it is compact, easy to carry d. cannot be recharged 42. Electrolyte of a storage battery if formed by adding a. water to hydrochloric acid c. hydrochloric acid to water b. sulfuric acid to water d. water to sulfuric acid 43. Induction instrument have found widest applications as a. voltmeter c. frequency meter b. ammeter d. watthour meter 5 44. Induction watthour meters care free from ________ errors a. phase c. temperature b. creeping d. frequency 45. Maxwell-Wien bridge is used for measuring a. capacitance c. inductance b. dielectric loss d. phase angle 46. The capacitance and dielectric loss of a capacitor is generally measured with the help of _________ bridge a. De Sauty c. Wien series b. Schering d. Anderson 47. The output voltage of a single loop generator is a a. steady dc c. pulsating dc b. steady ac d. pulsating ac 48. Electric dc generators have normally, an overall efficiency of the order of a. 60-80% c. 80-90% b. 75-85% d. 85-95% 49. The armature magnetic field has effect that a. it demagnetizes or weakens the main flux b. it cross magnetizes, or distorts it c. it magnetizes or strengthens the main flux d. (a) and (b) 50. In a dc generator, the flux seem to be ______ at the trailing pole tips and also _________ at the leading pole tips a. weakened, weakened c. crowded, weakened b. weakened, crowded d. same, same 51. Electric power is almost exclusively generated, transmitted and distributed by three phase system because it a. is more efficient b. use less material for a given capacity c. costs less than single phase apparatus d. all of the above 52. Interpoles are normally connected in a. parallel with the field c. parallel with the load b. series with the field d. series with the load 6 53. Carbon brushes are used in electronic motors to a. brush off carbon deposits on the commutator b. provide a path for flow of current c. prevent overheating of armature windings d. prevent sparking during commutation 54. If positive phase sequence of a 3 phase load is a-b-c, the negative sequence would be a. b-a-c c. a-c-b b. c-b-a d. all of the above 55. Power factor improvement a. does not effect the performance characteristics of the original load b. employs series resonance c. increases the active power drawn by the load d. increases the reactive power taken by the load 56. The chief disadvantage of a low power factor is that a. more power is consumed by the load b. current required for a given load power is higher c. active power developed by a generator exceeds its rated output capacity d. heat generated is more than the desired amount 57. In the two-wattmeter method of measuring three-phase power, the two wattmeter indicate equal and opposite readings when load power factor angle is ____ degrees lagging. a. 60 c. 30 b. 0 d. 90 58. When phase sequence at the three-phase load is reversed a. phase powers are changed b. phase currents are changed c. phase currents change in angle but not in magnitude d. total power consumed is changed 59. The method of symmetrical components is very useful for a. solving unbalanced polyphase circuits b. analyzing the performance of 3-phase electrical machinery c. calculating currents resulting from unbalanced faults d. all of the above 7 60. There are no transients in pure resistive circuits because they a. offer high resistance c. have no store energy b. obey ohm‟s law d. are linear circuits 61. The current flowing in the conductors of a DC motor is a. AC c. AC as well as DC b. DC d. transients 62. The torque of a motor is a. the force in N-m acting on the rotor b. the product of tangential force on the rotor and its radius c. the electrical power in kW d. the power given to load being driven by the motor 63. The speed of a series motor at no load is a. zero c. 3600 rpm b. 3000 rpm d. infinity 64. If the back emf in a DC motor is absent, then a. motor will run at very high speed b. motor will run at very slow speed c. motor will not run at all d. motor will burn 65. For both lap and wave windings, there are a many commutator bars as the number of a. poles c. slots b. armature conductors d. winding elements 66. The only function of dummy coils in a dc armature winding is to a. increase the induced emf b. render the average pitch an integer c. provide mechanical balance to the armature d. modify its electrical characteristics 67. Lap winding is suitable for __________ current, _________ voltage dc generators a. high,low c. low, low b. low, high d. high, high 8 68. The series field of a short-shunt dc generator is excited by _________ current a. shunt c. load b. armature d. external 69. Armature reaction is attributed to a. the effect of magnetic field set-up by the armature current b. the effect of magnetic field set-up by field current c. copper loss in the armature d. the effect of magnetic field set-up by back emf 70. If the resistance in a series RC circuit is increased, the magnitude of the phase angle a. increases b. remains the same c. decreases d. changes in an indeterminate manner 71. The current in RLC series circuit, i.e. at resonance is a. maximum c. infinity b. minimum d. zero 72. At a frequency less that the resonant frequency a. series circuit is capacitive and parallel circuit is inductive b. series circuit is inductive and parallel is capacitive c. both circuits are inductive d. both circuits are capacitive 73. In dc generators, armature reaction is produced actually by a. its field current b. armature conductors c. field pole winding d. load current in armature 74. Shunt generators are most suited for stable parallel operation because of their ________ voltage characteristics a. identical c. linear b. drooping d. rising 9 75. Two parallel shunt generators will divide the total load equally in proportion to their kilowatt output ratings only when they have the same a. rated voltage c. internal l aRa drops b. voltage regulation d. both (a) and (b) 76. The main function of an equalizer bar is to make the parallel operation of two over-compounded dc generators a. stable c. regular b. possible d. smooth 77. A coil with large distributed capacitance has a a. low resistance b. low Q c. low resonant frequency d. high resonant frequency 78. Which if the following is not a non-linear element? a. diode b. transistor c. heater coil d. electric arc with unlike electrodes 79. For maximum power transfer, according to maximum power transfer theorem, source impedance a. must be very much large as compared to the load impedance b. must be complex conjugate of load impedance c. must be equal to load impedance d. must be very small as compared to the load impedance 80. Ideal transformer assumptions do not include a. zero reactance of windings b. zero resistance of windings c. no leakage flux d. no saturation of core 81. If residual magnetism of a shunt generator is destroyed accidentally, it may be restored by connecting its shunt field a. to earth c. in reverse b. to an arc source d. to a dc source 10 82. An ideal generator is one that has __________ voltage regulation a. low c. positive b. zero d. negative 83. The __________ generator has poorest voltage regulation a. series c. shunt b. compound d. over compound 84. The counter emf of a dc motor a. often exceeds the supply voltage b. aids the applied voltage c. helps in energy conversion d. regulates its armature voltage 85. The resistance of low voltage side of a transformer a. is equal to resistances of its high voltage side b. is more than resistance c. is less than the resistance of its high voltage side d. (b) or (c) 86. What type of core is used for a high frequency transformer? a. air core c. aluminum core b. closed iron core d. open iron core 87. In any transformer the voltage per turn in primary and secondary remains a. always different c. always in ratio K b. always same d. sometimes same 88. The size of a transformer core will depend on a. frequency b. flux density of the core material c. area of the core d. both (a) and (b) 89. Under constant load conditions, the speed of a dc motor is affected by a. field flux c. back emf b. armature current d. both (b) and (c) 90. A series motor is best suite for driving a. lathes c. sheares and punches b. cranes and hoists d. machine tools 11 91. The shaft torque of a dc motor is less that it armature torque because of _____________ losses a. copper c. iron b. mechanical d. rotational 92. The speed of a dc motor ca be controlled by varying a. its flux per pole b. resistance of armature circuit c. applied voltage d. all of the above 93. High speed alternators have a rotor construction a. similar to dc machines c. of salient type b. of non-salient type d. none of the above 94. Distributing the armature winding of alternator in more than one number of slots per pole phase results in a. reduction of irregularities produced in waveform b. economy of materials used in winding c. less weight of the entire armature d. increase of generated emf per phase 95. When the power factor of load is unity, the armature flux of an alternator will be a. demagnetizing c. cross magnetizing b. square wave form d. none of these 96. The maximum current that can be supplied by alternator depends upon the a. strength of the exciter voltage b. number of poles c. strength of the magnetic field d. maximum heat dissipation 97. Controlled rectifiers employ a. diodes c. bridge circuits b. thyristors d. both (a) and (b) 98. When a 400Hz transformer is operated at 50Hz, its kVA rating is a. reduced to 1/8 c. unaffected b. increased 8 times d. increased 64 times 12 99. The primary and secondary windings of an ordinary 2-winding transformer always have a. different number of turns b. same size of copper wire c. a common magnetic circuit d. separate magnetic circuits 100. At relatively light loads, transformer efficiency is low because a. secondary output is low b. transformer losses are high c. fixed loss is high in proportion to the output d. Cu loss is small 101. Adjustment of field excitation on one of the two alternators operating in parallel will a. increase its load c. decrease its load b. change in frequency d. change its power factor 102. Synchronizing motors are a. self-starting c. essentially self-starting b. not self-starting d. none of these 103. A 3 phase synchronous motor is running clockwise. In case the direction of its field current is reversed a. the motor will continue to run in the same direction b. the motor will run in the reverse direction c. the motor will stop d. the winding of the motor will burn 104. The all-day efficiency of a transformer depends primarily on a. its copper loss c. the duration of load b. the amount of load d. both (b) and (c) 105. The essential condition for parallel operation of two single phase transformers is that they should have the same a. polarity c. voltage ratio b. kVA rating d. percentage impedance 106. Instrument transformers are used on ac circuits for extending the range of a. ammeters c. wattmeters b. voltmeters d. all of the above 13 107. The principle of operation of a 3-phase induction motor is most similar to that of a a. synchronous motor b. repulsion-start induction motor c. transformer with a shorted secondary d. capacitor-start, induction-run motor 108. When a 3 phase synchronous generator is supplying a zero pf lagging load the armature field affects the main field in the following way a. directly opposes it c. augments it directly b. cross-magnetizes it d. none of the above 109. Improvement in the power factor in an induction motor a. decreases torque b. increases the torque c. increases the current d. increases the torque and decreases the current due to increased impedance 110. Short circuit test on the induction motor can be used to find out a. the transformation ration of the impedance motor b. power scale of circle diagram c. copper losses in the induction motor d. all of the above 111. If the air gap of the induction motor is increased a. the magnetizing current will decrease b. the magnetizing current will increase c. the power factor will decrease d. none of the above 112. If starting winding of a single phase induction motor is left in the circuit, it will a. draw excessive current and overheat b. run slower c. run faster d. spark at light loads 113. If a single phase induction motor runs slower than normal, the more likely defect is a. improper fuses c. open starting winding b. shorted running winding d. worn bearings 14 114. A permanent split single-phase capacitor motor does not have a. centrifugal switch c. squirrel-cage rotor b. starting winding d. high power factor 115. Zero power method of an alternator is used to find its a. efficiency c. armature resistance b. voltage regulation d. synchronous impedance 116. Is a device which functions on failure of the insulation of a machine, transformer or of other apparatus to ground or on flash over of a dc machine to ground a. overhead ground relay c. grounding reactor relay b. ground insulation relay d. ground protective relay 117. Is an equipment which controls the gate or valve opening of prime mover a. silicon controlled rectifier c. rheostat b. contactor d. governor 118. Is the mechanism which is used for moving a removable circuit breaker unit to end from the connected, disconnected and test positions a. permissive control device b. notching device c. blocking device d. position changing mechanism 119. Is the complete electrical mechanism or servo-mechanism including the operator motor, solenoid, position, switches, etc., for a tap change, induction regulator or any piece of apparatus which has no device function number a. regulating device c. rotating device b. reversing device d. operating mechanism 120. Is use to increase or decrease in one step the value of field excitation on a machine a. tripping relay b. field regulator c. DC reclosing relay d. field changing contactor 121. A special type of diode used to regulate dc voltage supply a. Thyristors c. Diac b. Zener d. Shockley 15 122. Electrons normally flow a. from the grid to the plate of an electron tube b. from the positive terminal to the negative terminal inside the battery c. through a capacitor d. at the speed of light in a conductor 123. When an electric current is flowing in a conductor, heat is developed at a rate proportional to the square of the intensity of the current. This relation is known as a. Coulomb‟s law c. Faraday‟s law b. Joule’s law d. Ohm‟s law 124. An electric device designed to receive electrical power from a dc source and deliver alternating power without the aid of external source of alternating voltage a. amplifier circuit c. rectifier circuit b. oscillator circuit d. integrated circuit 125. The modulated wave is transmitted over lines or space. However at the receiving end, the signal wave must be recovered again by means of electronic circuit called a. frequency changer c. filter b. detector d. inverter 126. Process by which the characteristics of a wave is varied as a function of the instantaneous value of another wave a. detection c. phase shifting b. modulation d. feedback 127. In any network consisting of linear impedances, the current at any point is the sum of the currents that would flow if each generator were considered separated all other generators being replaced at the time by impedances equal to their internal impedances. This principle is known as a. Kirchhoff‟s law c. Thevenin‟s Theorem b. Superposition Theorem d. Reciprocity Theorem 128. When the emfs in the two windings of the transformer are opposite in direction, the polarity is a. positive c. additive b. negative d. subtractive 16 129. For a transducer, the impedance which will simultaneously terminate all of its inputs and outputs in such a way that each of its inputs and outputs, the impedances in both directions are equal are called a. iterative impedances c. characteristics impedances b. image impedances d. driving impedances 130. To determine the equivalent resistance of an inductive motor, we use a. no load test c. blocked rotor test b. short circuit test d. polarity test 131. Consisting of a single rotating machine that is mainly to convert alternating current to direct current a. motor generator set c. rotary converter b. motor converter d. mechanical rectifier 132. It is the ration of lumens reaching the work plane by the total lumens generated by lights a. maintenance factor c. coefficient of utilization b. room ratio d. room index 133. Intermittent operation in which the load conditions are regularly recurrent a. short time duty c. periodic duty b. continuous duty d. varying duty 134. In a dc machine, this consists of coils placed at the neutral point midway between the main poles a. compensating winding c. interpole winding b. equalizer winding d. neutralizer winding 135. A connection to ground for one or more non-carrying metal parts of the wiring system or apparatus connected to the system a. system ground c. equipment ground b. system neutral ground d. capacitive ground 136. A transformer intended primarily to provide neutral point for grounding purposes a. ground regulating transformer b. ground equalizer transformer c. grounding transformer d. ground fault transformer 17 137. A grounding transformer may be connected zigzag of a. delta-delta c. wye-delta b. delta-wye d. wye-wye 138. Of the lighting arresters sold in the market, which can handle much surge current and excessive contamination of dirt a. distribution arrester c. station arrester b. line arrester d. intermediate arrester 139. It is a disruptive discharge between electrodes of measuring gap, voltage control gap, or protective device a. flashover c. sparkover b. corona d. fireover 140. The voltage that insulation is capable of withstanding without failure or disruptive discharge when tested under specified conditions a. maximum withstand voltage b. rated withstand voltage c. c. critical withstand voltage d. minimum 141. In symmetrical components, the components consisting of balanced 3 phase vectors and having a phase sequence opposite to that of the given vector is a. additive sequence system b. subtractive sequence system c. negative sequence system d. positive sequence system 142. The fault current that exists immediately after the fault is known as a. transient current c. subtransient current b. steady state current d. sustained current 143. The insulation strength of an equipment is described as its a. basic insulation strength c. basic insulation level b. basic impulse stress d. basic insulation factor 144. In hydroelectric power plant, it is used to prevent the sudden rise and drop of water pressure. a. penstock c. dam b. intake tower d. surge tank 18 145. To test the accuracy of a kilowatthour meter an electrician used a wattmeter. He found out that the meter makes 5 revolutions in 18 seconds. The meter constant is 3.2. What is the percent error if the wattmeter reading is 3,368? a. 8% slower c. 5% slower b. 8% faster d. 5% faster 146. A 100 MW power plant burns 0.4 kg of coal with heating value of 7.2 x 106 calories per kg to produce 1 KwHr. If the power plant acts as a base load, how many tons of coal per day is consumed if the power plant operates 24 hours per day? a. 530 c. 830 b. 960 d. 260 147. An amplifier has an output of 50 watts. What is its output in dbm? a. 47 c. 75 b. 50 d. 80 148. How is the storage battery rated in capacity? a. volts c. amperes b. watts d. ampere – hour 149. The basis where the flow of current is from positive to negative was derived from _____ a. superstition c. scientific b. tradition d. convention 150. A 220 volts dc series motor when running at 800 rpm draws a current of 100 amperes. The combined resistance of the armature and the field is 0.1 Ω. What is the speed when the motor develops one – half of the original torque? a. 1,600 rpm c. 1,147 rpm b. 1,690r pm d. 1,225 rpm 151. The fault current that exists immediately after the fault is known as: a. sub – transient current c. steady – state current b. transient current d. sustained current 152. Its primary function is to provide ground source a. zig – zag transformer c. surge arrester b. sectionalizer d. tertiary transformer 19 153. The following are the given loads of a particular circuit: 5 – 15 hp motors 3 – 5 hp motors 8 kw – lighting loads 3.5 kw – miscellaneous loads Calculate for the maximum demand if the demand factor is 65%. a. 78.64 c. 51.12 b. 45.81 d. 120.98 154. An SCR‟s three leads are the: a. anode, cathode and emitter b. anode, cathode and gate c. base 1, base 2, and emitter d. main terminal 1, main terminal 2, and gate 155. A 20 kv/7.87 kv autotransformer has a secondary line current of 100 A. What is the current in the common winding? a. 139.25 A c. 60.65 A b. 100 A d. 39.35 A 156. A 220 volts single – phase induction motor draws current of 10 amperes at 0.75 power factor. A capacitor of 50 µF is connected in order to improve the power factor. What is the new power factor? a. 0.866 leading c. 0.95 lagging b. 0.866 lagging d. 0.95 leading 157. A 3Φ 220 volts, 10 hp induction motor having a power factor of 0.8 has 3% losses. Determine the current drawn by the motor. a. 25.23 A c. 20.18 A b. 43.69 A d. 14.56 A 158. A solenoid having an inductance of 12 henry is impressed across a voltage source such that the current through it is 3 amperes. What is the average voltage at t = 0.2 sec? a. 150 volts c. 120 volts b. 180 volts d. 220 volts 20 159. An electric heater takes 23.889kcal in 20 minutes at 200 volts. What is the current drawn by the heater? a. 8.4 A c. 1.67 A b. 16.67 A d. 0.42 A 160. A series RLC circuit has a resistance of 15 Ω and an inductive reactance of 1,500 Ω. What is the Q – factor of the circuit at resonance? a. 120 c. 140 b. 100 d. 150 161. A synchronous motor that is used for power factor correction only. a. synchronous reactor c. generator b. alternator d. synchronous condenser 162. Why are transmission towers sometimes constructed in lattice type and sometimes in pole type although they have the same capacity and voltage rating? a. reliability c. right of way b. wind load d. safety 163. The capacitive reactance of a transmission line is 90,000 ohms per kilometer. Find the total capacitive reactance if the transmission line is 50km long. a. 4.5x 106 Ω c. 90,000 Ω b. 1,800 Ω d. 180,000 Ω 164. An 80 µF capacitor in series with 1,000 Ω resistor is connected suddenly across a 110 V supply. Find the rate at which current begins to decrease. a. 13.75 A/s c. 1.375 A/s b. 0.1375 A/s d. 137.5 A/s 165. A 100 watts 230 volts gas fitted lamp has a mean spherical candlepower of 92. Find its efficiency in lumens per watt. a. 11.56 c. 115.6 b. 1.156 d. 1,156 166. Charges that are both positively and negatively charged are called: a. negatron c. neutron b. neutraton d. positron 21 167. With the primary of CT energized, the secondary must never be made open to prevent this to happen. a. build up of magnetic bias b. burning of primary winding c. burning of secondary winding d. absence of induced voltage 168. A 25 miles (40 km), 3Φ, 3 wire sub transmission line with an impedance per conductor of (7.65 + j16.52) Ω is supplying a balanced 3Φ load of 4,000 kw, 33,500 volts line to line, 60 hz at 0.8 p.f. lagging. The conductors used in the line are 336.4 MCM, ACSR, 26/7 strands vertically spaced 4.5 ft apart. If a 2,100 kvar, 3Φ pure capacitor bank is installed across the load, what is the voltage dip maintaining 33,500 volts at the receiving end? a. 735 V c. 585 V b. 635 V d. 485 V 169. A symmetrical cable with 200 meters span has a unit weight of 2 kg-force per meter uniformly distributed along the horizontal. The tension at the lowest point is 2,000 kg-force. Find the tension at the supports in kg-force. a. 2,010 c. 4,080 b. 2,040 d. 2,000 170. The positive-sequence components of the system has a. the same phase-sequence as the original b. the opposite phase-sequence as the original c. zero-phase displacement d. both a and b 171. A voltmeter rated 150 volts has an internal resistance of 10 kΩ. What resistance should be added in series to the internal resistance so that the voltmeter will register full scale deflection across 450 V? a. 6.67 kΩ c. 40 kΩ b. 30 kΩ d. 20 kΩ 172. Pilot lamp in a MCC indicates a motor control center a. underload b. overload c. normal condition of the load d. out of order 22 173. A south pole 20 unit pole is placed one inch away from another south pole 35 unit pole. What is the force between the two poles? a. 108.5 dynes repulsion c. 70 dynes repulsion b. 108.5 dynes attraction d. 70 dynes attraction 174. In a 34.5 kv three-phase system, the Thevenin‟s equivalent impedances are Positive impedance, Z1 = 0.015 p.u. at 50 MVA Zero impedance, Z0 = 0.03 p.u. at 50 MVA What is the phase to phase fault current? a. 48,000 A c. 8,400 A b. 80,000 A d. 32,000 A 175. This is an electrically operated switch which is rated in amperes and is also used in overload protection of motors. a. magnetic starter c. magnetic contractor b. safety switch d. manual starter 176. These are high intensity discharged lamps which are usually installed in outdoor and wide areas and are mounted on poles whereas for indoors these are used for high ceiling applications. a. surfaced c. low mount b. recessed d. high bay 177. What do you call an insulated conductor that can be used only up to 300 volts and is considered having no insulation base on general rating? a. insulated conductor c. enameled conductor b. base conductor d. covered line wire 178. What is the field intensity E in millivolts per meter of an omnidirectional antenna over a distance of 1 km if the power is 1 kw? (impedance of free space is 120∏) a. 153.4 c. 120 b. 150 d. 173.32 179. A limit switch is used to shut off the power when _____ a definite limit. a. current exceeds c. the travel reaches b. voltage falls below d. frequency exceeds 23 180. A magnetic circuit consists of silicon steel of 2000 permeability of 10 cm length and cross sectional area and of 1 centimeter length. A one – ampere current flows through 500 turns of coil. Calculate the field intensity across the air gap. a. 622 Oersted c. 590 Oersted b. 755 Oersted d. 350 Oersted 181. Find the GMD of a double circuit having vertical configuration 3 meters apart and 3 meters between conductors. The phase configuration of the 1st circuit is ABC from top to bottom and the 2nd circuit is CBA. a. 4.24 m c. 3.567 m b. 3.78 m d. 3 m 182. A relay coil carries a polarizing current of 1 A dc and a signal ac current of 3 A at 50 hz. If coil resistance is 5 Ω, power dissipated by the coil is ___ watts. a. 50 c. 5 b. 80 d. 20 183. For a 4-pole dc generator, having a progressive simplex 2- layer wave – winding with 30 conductors, the commutator pitch is ___ a. 8 c. 10 b. 9 d. 11 184. Rapid stopping of an electric motor by momentarily reversing its connections to the supply is called a. jogging c. plugging b. inching d. sequence operation 185. A certain 1Ф load takes 10 kw at 75 percent power factor. In the power contract the power factor penalty is applied only to power factors below 85 percent. What size of capacitor must be used in order to avoid the penalty? The voltage is 550 volts, 60 cycles. a. 92.82 µF c. 2.98 µF b. 9.82 µF d. 22.98 µF 186. An induction motor driven above synchronous speed is called ___. a. induction regulator c. centrifugal switch b. zero – speed switch d. limit switch 24 187. A 200 kva transformer has an impedance of 15% and the power factor of the load is 85%. The primary voltage is 6,000 volts while the copper loss is 15 kw. Find the percentage voltage regulation. a. 13.49% c. 8.91% b. 15.78% d. 23.67% 188. What is the speed of an induction motor of six poles if the percent slip is 2.5%? a. 1462 rpm c. 877 rpm b. 1170 rpm d. 1755 rpm 189. The rotor poles of an 8 – pole synchronous generator shift by 10 mechanical degrees from no –load to full – load. Calculate the torque angle between the excitation voltage E 0 and the terminal voltage VФ at full – load. a. 10º c. 30º b. 20º d. 40º 190. This is a device projected vertically upward above structures to serve as the lighting rod. a. air connector c. air terminal b. lightning bowl d. air rod 191. A transformer is designed to carry 30 times its rated current for 1 second. The length of time that a current of 20 times the rated current can be allowed to flow is a. 0.67 sec. c. 1.5 sec b. 2 sec d. 2.25 sec. 192. What is the normal secondary circuit current of a current transformer? a. 15 A c. 5 A b. 20 A d. 10 A 193. A parallel circuit has branch resistance of R 1 =20 Ω, R2 =10 Ω, R3 =5 Ω. If the current passing through R 1 =20 Ω resistor is 1 ampere, what is the current passing through the 10 Ω resistor? a. 5 A c. 3 A b. 2 A d. 4 A 25 194. In a stranded conductor, what do you call the strand at the center of the conductor? a. king wire c. steel wire b. center wire d. center 195. The total power consumed by a balanced 3Ф load is 3,000 watts at 80% power factor. Two wattmeters WA and WB are connected to the line. What is the reading of WA? a. 2,150 watts c. 1,500 watts b. 2,000 watts d. 2,500 watts 196. A circuit with a resistance of 10 Ω is supplied with 120 V 60 hz source. What is the phase angle between the voltage and the current? a. 45º c. 30º b. 15º d. 0º 197. What is the synchronous speed in rpm of a 6 - pole 60 cycle induction motor? a. 1,200 c. 3,600 b. 1,800 d. 900 198. A 3 phase 4 wire system has the following unbalanced loads: Z1= (10+j5) Ω, Z2= (8+j4) Ω and Z3= (20+j0) Ω. The line to neutral voltage of the system is 120 volts. What is the reading of the wattmeter in watts in Z3? a. 900 c. 1,000 b. 720 d. 1,050 199. What electrode in a junction transistor corresponds to the cathode in vacuum tube? a. base c. drain b. emitter d. collector 200. An AC circuit with two resistances, which is correct? a. a 1,000 ohm resistance in series to 500 ohm has a total of 6,000 ohms. b. Two 1,000 ohm resistances in series has a total of 1,500 ohms. c. Two 1,000 ohm resistances in series has a total of 707 ohms d. Two 1,000 ohm resistances in series has a total of 2,000 ohms. 26 201. Which does not belong? a. lines per square centimeter b. maxwells per square centimeter c. flux d. gauss 202. The diameter of a conductor is 0.064 inch. What is the area in circular mils? a. 5,000 c. 3,217 b. 10,000 d. 4,096 203. In a shunt motor, what is the relative connection of the armature winding with respect to the field winding? a. series c. series – parallel b. parallel – series d. parallel 204. A single – phase 2,400 volt synchronous generator draws 450 amperes at unity power factor. The synchronous impedance of the generator is (0.08 + j2.8) Ω. What is the regulation in percent? a. 14.2 c. 20.1 b. 16.3 d. 18.4 205. A pure semiconductor without doping is called a. contaminated c. doped b. extrinsic d. intrinsic 206. A series RLC circuit has R = 10 Ω, L = 40 x 10 -6 H and C = 60 x 10-12 F. What is the resonant frequency of the circuit in MHZ? a. 20.17 c. 4.49 b. 3.24 d. 1.62 207. On full – load a 500 volt series motor takes 100 amperes and runs at 840 rev/min. The armature resistance is 0.1 ohm and field resistance is 0.04 ohm. Find the speed when developing half of full – load torque but with a 0.08 ohm diverter in parallel with the field winding. Assume flux is proportional to the field current. a. 640 rpm c. 1,464 rpm b. 1,020 rpm d. 1,360 rpm 27 208. A capacitor charged with 10,000 µC. If the energy stored is 1 joule, find the capacitance. a. 500 µF c. 5,000 µF b. 5 µF d. 50 µF 209. A 440 volt synchronous motor is taking 50 amperes at a p.f. of 0.9 lagging. The effective resistance of armature is 0.8 ohm. If the iron and friction losses amount to 600 watts, find the horse power output. a. 25.7 c. 23.1 b. 37.1 d. 40.5 210. Three 100 µF capacitors are connected in delta to a 500 volt, three phase, 50 Hz supply. Find the line current. a. 15.71 A c. 31.83 A b. 27.21 A d. 8.66 A 211. A pair of copper mains. Each of 3.87 square centimeters cross section is used to transmit power a distance of 915 meters. For 10 hours a day, 80 kW at 200 volts are taken from the mains. Find the energy lost in the cables per day. Take ρ = 1.7 micro ohm – cm. a. 64 kW-hr c. 256 kW-hr b. 128 kW-hr d. 32 kW-hr 212. An SCR combines the features of a. a rectifier and resistance b. a rectifier and capacitor c. a rectifier and transistor d. a rectifier and inductor 213. A 0.09 microfarad capacitor is charged to 220 volts. How long in milliseconds will it discharged to a level of 110 volts if the discharged resistor has a resistance of 20,000 ohms? a. 1.5 c. 1.25 b. 2.5 d. 0.5 214. The total generating capacity of a power plant is 1,600 kva. The total connected load is 2,500 kva. Average load is 1,145 kva. The maximum power demand is 1,150 kva. What is the plant factor? a. 46% c. 71.88% b. 99.5% d. 71.56% 28 215. Assuming the most efficient technologies for the extraction of energy, the fuel with the largest known reserves is a. coal c. natural gas b. oil d. nuclear 216. A three – phase 60 hz line has flat horizontal spacing. The conductors have an outside diameter of 3.28 cm with 12 m between conductors. Determine the capacitive reactance of the line to neutral if its length is 125 miles. a. 1.62 x 103 Ω c. 25.3 x 106 Ω b. 202.4 x 103 Ω d. 16.2 x 103 Ω 217. Name of the transformer that provides an almost continuously variable step-less output voltage from zero to rated line voltage. a. booster c. AVR b. UPS d. Variac 218. A circuit has a resistance of 20 Ω and a reactance of 30 Ω. What is the p.f. of the circuit? a. 0 c. 0.832 b. 0.55 d. 0.99 219. A parallel branch circuit composed of a 100 ohm resistance, 150 ohm capacitive reactance and 90 ohm inductive reactance. What is the total impedance of the circuit? a. 125 c. 91 b. 100 d. 97 220. The most common type of the conductor used for overhead transmission lines consisting of electrical grade aluminum conductor overlaying strands of high carbon galvanized steel is called: a. ACAR c. COMPACT STAND AL b. ACSR d. AAC 221. The 65 percent taps on a compensator are used in connection with a 10 hp 220 volt three phase motor. Rated motor current is 26.4 amp, and blocked – rotor current at 220 volts is 150 amp. Calculate the percent motor current in terms of rated amperes. a. 369 c. 240 b. 65 d. 568 29 222. A single – phase transformer is rated 110/440 V, 2.5 kVA. Leakage reactance measured from the low – tension side is 0.06 Ω. Determine leakage reactance in per unit. a. 0.0484 c. 0.484 b. 0.0248 d. 0.0124 223. Three capacitors of 50 µF, 30 µF, and 10 µF are connected in parallel. What is the total capacitance in microfarad? a. 15 µF c. 100 µF b. 90 µF d. 115 µF 224. What is the process of heating electrically non metallic materials such as plumber plastics, etc.? a. resistive c. dielectric b. capacitive d. induction 225. If a fault occurs near a generating station, how long does the transient component of the fault last? a. 10 to 15 sec c. 3 to 5 sec b. 5 to 10 sec d. 1 to 3 sec 226. A three – phase 60 Hz, 30 mile transmission line delivers 20,000 kW at 69,000 volts and 75% power factor lagging. The resistance of the line is 0.3 ohm per mile and the reactance is 0.7 ohm per mile. What is the transmission line efficiency? a. 93 c. 95 b. 94 d. 96 227. How are multiple stop push buttons connected in a control circuit? a. combination series – parallel b. parallel c. gang d. series 228. A road is illuminated by two 500 candela lamps placed 6.1 meters above the center line of the road and 18.3 meters apart. Find the illumination produced on the surface of the road at a point on the center line midway between lamps. a. 2.29 lux c. 9.16 lux b. 4.58 lux d. 18.32 lux 30 229. A heater contains 1.6 kg of water at 20ºC. It takes 12 minutes to raise the temperature to 100ºC. Assume the losses due to radiation and heating the kettle to be 10 kcal. Find the power rating of the heater in kW. a. 0.74 c. 0.84 b. 0.7 d. 0.8 230. Shunts are generally made of what material? a. constantan c. aluminum b. silver d. manganin 231. A magnetizing force of 1,000 At/m will produce a flux density of ____ in air. a. 1.257 mWb/m2 c. 1.257 Wb/m2 2 b. 0.63 Wb/m d. 0.63 mWb/m2 232. The potential difference of a battery is 10 volts when the current is 1.5 amperes and 8 volts when the current is 2.5 amperes. Find the internal resistance of the battery. a. 1 Ω c. 3 Ω b. 2 Ω d. 4 Ω 233. A four pole, lap wound armature when driven at 600 rpm generates 120 V. If the flux per pole is 25 mWb, find the number of armature conductors. a. 120 c. 480 b. 240 d. 720 234. A coil of 1,000 turns is uniformly wound on ring of non – magnetic material, the mean diameter being 0.2 meter. The cross –sectional area of the coil is 4 cm 2, with a current of 2 amperes flowing, find the total flux in µWb. a. 3.2 c. 1.6 b. 6.4 d. 4.8 235. What are the three colors which when mixed equally together will produce white and the combination of any two will produce different colors and intensities? a. red, blue, green c. black, red, pink b. yellow, magenta, cyan d. red, blue, yellow 236. A 500 kV line is categorized as a. high voltage c. extra high voltage b. ultra high voltage d. medium voltage 31 237. A circuit having a resistance of 20 Ω and an inductance of 0.5 H is connected suddenly across a 220 V supply. Find the rate of increase of current at the instant of closing the switch. a. 440 A/s c. 120 A/s b. 220 A/s d. 480 A/s 238. A 350 kW, 2,300 V, three – phase resistive load is measured with two small wattmeters. Two 100/5 A current transformers and two 2,300/115 V potential transformers make this possible. Calculate the reading on each wattmeter. a. 874 W & 874 W c. 1,311 W & 1,311 W b. 218 W &218 W d. 437 W & 437 W 239. The transformer is rated at 550/220 V. With the low –voltage winding shorted, it requires 25 V across the 550 V winding to permit rated current through both windings of the transformer. Calculate the percent impedance. a. 4.55% c. 3.55% b. 5.55% d. 6.55% 240. A group of 10 luminaries, each with two 40 watt, cool – white fluorescent lamps, are installed in a classroom. An appropriate CU of 0.65 is selected from the manufacturer‟s chart, which also suggests an MF of 0.85. Determine the total lumens output of the luminaries. a. 58,000 c. 32,100 b. 26,000 d. 64,200 241. A central station has annual factors as follows: Load = 58.5% Capacity = 40.9% Use = 45.2% The reserve carried over and above the peak load is 8,900kw. What is the installed capacity? a. 20,700 kW c. 25,900 kW b. 29,600 kW d. 40,000 kW 242. A 12 µF capacitor charged at 500 volts and a 6 µF capacitor charged at 250 volts are connected in parallel. What is the potential difference of the combination? a. 750 V c. 375 V b. 500 V d. 417 V 32 243. An antenna that transmits or receives equally well in all directions is said to be __________ a. omni directional c. unidirectional b. bi-directional d. quasi-directional 244. A 30 mile transmission line is to deliver 20,000 kW at 69 kV at 85% power factor. The line resistance is 0.324 ohm per mile and inductive reactance is 0.737 ohm per mile. What is the line loss? a. 1,050 kW c. 997 kW b. 376.7 kW d. 1,130.3 kW 245. Prior to starting of fluorescent lamp, heating of electrode is done by a. starter c. filament b. ballast d. heater 246. A frequency of 27 MHz has a wavelength of approximately______. a. 11 m c. 27 m b. 30 m d. 81 m 247. A type of communication that uses light rather than electricity to communicate is called_____. a. laser carrier c. powerline carrier b. microwave d. fiber optic 248. A copper wire has a diameter of 0.032 inch. What is the area in circular mils? a. 1,288 c. 810 b. 1,024 d. 1,624 249. It is required to increase the power factor of a 750 kW three – phase balanced load from 70% lagging to 90% lagging. The line voltage is 6,900 volts, 60 hz. Specify the capacitor required to increase the power factor of this wye – connected load in microfarad per phase. a. 20.45 c. 18.58 b. 22.39 d. 17.22 250. A signal occupies the spectrum space from 1.115 to 1.122 GHz. The bandwidth is____. a. 0.007 MHz c. 237 MHz b. 700 MHz d. 7 MHz 33 251. Two condensers of 3 and 5 µF respectively are connected in parallel. The combination is charged with 0.0056 coulomb. What is the charge in the 3 µF condenser in coulombs? a. 0.01 c. 0.0021 b. 0.005 d. 0.0035 252. A series circuit with 10 ohm resistor and 50 µF capacitor is suddenly connected to a dc source of 120 volts. What is the current at one time constant? a. 12 A c. 7.6 A b. 2.44 A d. 4.4 A 253. A room with dimensions of 72 ft x 36 ft x 13 ft requires 50 footcandles, maintenance factor of 0.7 coefficient of utilization of 0.46 and Rl of 4. Calculate the required lumens output of the lamps. a. 144,000 c. 402,485 b. 136,800 d. 74,690 254. Instrument transformers are used in indicating and metering and with protective devices, they are used for ______ a. measuring c. relaying b. detecting d. sensing 255. Reactances are connected in series: Xc1=100, Xc2=40, XL1=30, XL2=70. What is the net reactance? a. 80Xc c. 60XL b. 40Xc d. 50XL 256. A tuned circuit is resonant at 4 MHz. Its Q is 100. What is its bandwidth? a. 4 kHz c. 400 Hz b. 400 kHz d. 40 kHz 257. What is the value of Rx in kohms to be connected in parallel to a 75 kohms to reduce the value of total resistance to 10 kohms? a. 11.7 c. 7.5 b. 15.7 d. 12.7 258. What is the burning hours that should be used in the design consideration of incandescent bulb? a. 1,500 c. 850 b. 1,800 d. 650 34 259. Three capacitors of 3, 4 and 5 microfarads are connected in series with a 6 volt battery. When the current stops, what is the voltage across the 3 microfarad capacitor? a. 1.62 V c. 2.55 V b. 1.91 V d. 1.53 V 260. A transformer rated 2,000 kVA, 34,500/240 volts has 5.75% impedance. What is the per unit impedance? a. 0.0636 c. 0.0575 b. 0.0656 d. 34.2 261. It refers to a device that merely boosts a signal and passes it on. a. amplifier c. op – amp b. booster d. repeater 262. What do you call an impedance that when a line to ground fault occurs, produces fault currents that are equal and in – phase? a. positive sequence c. negative sequence b. third sequence d. zero sequence 263. If 14,000 maxwells emanate from a pole, what must be its area to have a flux density of 7,000 gauss? a. 3 cm2 c. 2 cm2 b. 4 cm2 d. 1 cm2 264. In a series or parallel LC circuit, the resonant frequency is attained when a. Xc is 1/10 of XL c. Power factor angle is 90° b. XL is 1/10 of XC d. Xc = XL 265. A light source has an illumination of 100 footcandles (fc), what is the illumination in lux? a. 1,204 c. 1,496 b. 1,075 d. 1,360 266. What is the equivalent of the collector terminal of transistor in a FET? a. grid c. source b. gate d. drain 35 267. What is the percent slip of the synchronous motor when running? a. 3 c. 1 b. 2.5 d. 0 268. If you tuned in a FM radio station ranging from 88 MHz to 108 MHz, what is the maximum capacitance in picofarads if L = 0.1 microhenry? a. 34.5 c. 32.7 b. 38.6 d. 36.8 269. In an induction motor, what is the percent slip if the speed is 3,510? a. 1 c. 2 b. 1.5 d. 2.5 270. What is the unit of electrical resistance? a. volt c. ohm b. ampere d. watt 271. Three equal resistors are connected in series. The voltage in one of the resistors is 15 volts. What is the applied voltage? a. 30 V c. 40 V b. 45 V d. 50 V 272. An ideal full wave rectifier with non inductive load has zero transformation losses. What is the efficiency? a. 100 c. 80 b. 90 d. 70 273. A 750 Hp, 2,400 volts three –phase motor has a power factor 90% and efficiency of 95% is to be operated to a 13.2 kV utility service thru a wye – delta connected transformer. What is the total kVA of the transformer bank? a. 575 c. 595 b. 654 d. 615 274. What category do 115 kV – 230 kV belong? a. low voltage c. high voltage b. medium voltage d. extra high voltage 275. What is the device that converts DC power to AC? a. converter c. SCR b. inverter d. Rectifier 36 276. A voltmeter has a resistance of 80 ohms per volt deflection. What current will flow in milliamperes (mA) when connected across 150 volt source if it has a 200 volt scale deflection? a. 11.5 c. 9.4 b. 10.5 d. 12 277. The power drawn by a balanced 3Φ load is 3,000 watts at 80% power factor. If two wattmeters WA and WC are used, what is the reading of WC? a. 800 c. 900 b. 950 d. 850 278. What is the most common cause of failure in cable termination and splicing? a. tracking b. poor shielding c. wrong clearance d. improper insulation penciling 279. In a series RLC circuit, the resistance is 200 Ω, the inductance is 10 mH, and the capacitance is 4 µF. If the circuit is connected across 100 volt source, what is the current? a. 0.144 c. 0.12 b. 0.15 d. 0.13 280. A 3,600 V 500 kVA 60 Hz 3 phase Y – connected generator on test yields the following results: Mechanical and iron losses is 10 kW; field current at full – load 100% p.f. is 50 A; field current at full – load 80% p.f. is 70 A; resistance per phase of armature winding is 0.4 ohm. The exciter voltage is constant at 120 volts and voltage control is done by means of rheostat. Determine the full – load armature current at 80% lagging p.f. a. 95.6 A c. 64.2 A b. 99.8 A d. 80.2 A 281. Three of the following terms in magnetic induction are identical. Which is distinct among the following? a. maxwells c. flux b. lines d. gauss 282. One kW-hr is equal to a. 3,600 watts c. 860 k calories b. 1,000 watts d. 4,186 newtons 37 283. A power plant is driven by a turbine at a rate of 10 cubic meters per second and with a head of 235 meters. If the plant efficiency is 0.65, calculate the power plant output. a. 10,000 kW c. 35,000 kW b. 15,000 kW d. 25,000 kW 284. At a certain point in a 69 kV transmission line, the positive sequence impedance is j0.15 p.u., and the zero – sequence impedance is j0.55 p.u. Calculate the fault current if a line – to – line fault occurs. The base is 50 MVA. a. 3,511 amperes c. 420 amperes b. 1,890 amperes d. 2,414 amperes 285. A 3Φ, 220 volt, 10hp induction motor having a power factor of 0.8 has 3% losses. Determine the current drawn by the motor. a. 25.23 amps c. 20.18 amps b. 43.69 amps d. 14.56 amps 286. The three phase unbalanced currents are: Ia = 10 cis (-30°) Ib = 0 Ic = 10 cis (150°) Find the negative sequence current of phase a. a. 8.66 cis 30 c. -5.77 b. 5.77 cis (-60) d. 5.77 287. A test is performed on a 230 volts, delta connected synchronous motor having 92% efficiency and 85% power factor. With 6 volts dc impressed across its terminals, the current reading is 90 amperes. Determine the ohmic resistance per phase. a. 0.067 Ω c. 0.1 Ω b. 0.044 Ω d. 0.15 Ω 288. A 20 Hp, 110 V dc shunt motor has an efficiency of 88% and an exciting current of 4 amperes and an armature resistance of 0.04 ohm. What starting resistance is required for full load torque? a. 0.98 Ω c. 0.95 Ω b. 0.94 Ω d. 0.69 Ω 38 289. A 100 km transmission line has a 1,200 ohms shunt reactance. What is the per km shunt reactance? a. 1,200 Ω c. 12 Ω b. 120,000 Ω d. 120 Ω 290. What is the total energy generated by a station in kWHr in a year if its maximum demand and annual load factor is 150 kW and 45% respectively? a. 591,300 c. 24,637 b. 1,314,000 d. 67,500 291. When luminaries direct 90 to 100% of their output downward is considered a ______. a. direct lighting c. indirect lighting b. local lighting d. luminaries 292. A three phase squirrel cage motor is started by a wye – delta starter. What shall be its starting torque relative to its rated voltage starting torque? a. 33.3% c. 57.7% b. 42.3% d. 100% 293. It took a heater of 2 kW, 158 minutes to raise by 30°C the temperature of water in an insulated vessel. How many gallons of water are inside the vessel? a. 30 gallons c. 40 gallons b. 10 gallons d. 20 gallons 294. A certain shunt motor armature has a resistance of 0.07 Ω and current of 50 amperes at 120 volts. Determine counter emf. a. 108.5 V c. 112.2 V b. 116.5 V d. 118.3 V 295. The kH of kWHr meter is 3.2. The disc takes 32 seconds to complete one (1) revolution. What is the load rating? a. 0 c. 360 watts b. 800 watts d. 2.1 watts 296. In a balanced 3Φ system the phase a voltage is 132.8 cis 0°, what is the line to line Vca voltage? a. 230 cis 30° c. 230 cis (-60°) b. 230 cis (-30°) d. 132.8 cis 120° 39 297. The instantaneous value of the voltage is given by its equation v = 105 sin ωt – 25 sin 3ωt + 15sin (6ωt- 30°). What is its rms value? a. 77 volts c. 105 volts b. 190 volts d. 205 volts 298. A dc shunt motor develops 15 Hp at 120 V. If the effective armature resistance is 0.061 ohm and the field winding draws 2 amperes, what is the overall efficiency? a. 90% c. 95% b. 93% d. 94% 299. V12 = 100 cis 30° and V23 = 50 cis 120°. Evaluate V12 - V23. a. 62 cis 6.2° c. 111.8 cis 3.4° b. 127.3 cis 40° d. 62 cis (-6.2)° 300. A 200 microfarad capacitor is connected in series with a 10 Ω resistor. The circuit is connected to a 24 V battery. What is the initial current when putting the switch on? a. 1.2 A c. 0.255 A b. 2.4 A d. 0.0125 A 301. The percent impedance of a line is 6% at 34.5 kV and 100 MVA base. What is the ohmic impedance? a. 2.32 c. 0.72 b. 3 d. 1.2 302. The rms value of sinusoidal ac current is equal to its value at an angle of ___ degree. a. 60 c. 30 b. 45 d. 90 303. Transformer are rated in kVA instead of kW because a. load power factor is often not known b. kva is fixed whereas kw depends on load c. total transformer loss depends on volt – ampere d. it has become customary 304. A synchronous motor having 40% reactance and a negligible resistance is to be operated at rated load unity p.f. If the motor is rated 100 volts and 100 A, what is the value of induced emf? Assume delta connected motor. a. 180 V c. 4001 V b. 70 V d. 108 V 40 305. The starting winding of a single – phase motor is placed in the a. rotor c. armature b. stator d. field 306. What is the current per phase in the primary windings of a 3 phase ∆/Y connected 6,600/400 V, 500 kVA, 50 Hz transformer. Neglect no – load current. a. 43.74 A c. 14.58 A b. 75.76 A d. 25.25 A 307. A 3 Hp 208 volt three phase motor is started by the Y - ∆ method. If the starting current is 54 amp when rated voltage is applied, what current will flow when the Y - ∆ switch is used? a. 93.5 A c. 31.2 A b. 162 A d. 18 A 308. An 80:5 current transformer is connected to a 5 amp ammeter. If the latter registers 3.65 amp, what is the line current? a. 58.4 A c. 21.9 A b. 80 A d. 3.65 A 309. It is desired to purchase a synchronous condenser to correct the 2,400 kVA 0.67 lagging p.f. load in an industrial plant to 0.95 lagging. Neglecting losses, calculate the kVA input rating of the required synchronous condenser. a. 2,280 kVA c. 1,500 kVA b. 1,608 kVA d. 1,250 kVA 310. The armature of a 230 volt shunt motor has a resistance of 0.18 ohm. If the armature current is not to exceed 76 amp, calculate the resistance that must be inserted in series with the armature at the instant of starting. Assume a 2 volt drop at the brushes. a. 2.82 Ω c. 3.18 Ω b. 3 Ω d. 2.69 Ω 311. It is desired to step down the three phase voltage from 6,600 to 460 volts using Y - ∆ transformer connection. What should be the ratio of transformation of each transformer? a. 1:8.3 c. 1:14.3 b. 14.3:1 d. 8.3:1 41 312. In a laboratory experiment, the impedance of a coil was obtained at 60 Hz and 30 Hz. These are 75.48 ohms and 57.44 ohms, respectively. What is the inductance of the coil? a. 150 mH c. 42.5 mH b. 182.5 mH d. 2.1 mH 313. A power customer is applying for source and listed the following loads: 5 – 15 Hp motors 3 – 5 Hp motors Lighting loads – 8 kW Miscellaneous loads 3 – 5 kW The demand factor is 65%, load factor is 46% and the power factor is 80%. What is the maximum kW demand of the customer? a. 78 c. 69 b. 64 d. 57 314. A 250km transmission line has the following parameters: resistance per km 0.05 ohm, capacitive reactance per km 625,000 ohms and inductive reactance per km 0.2 ohm. What is the series impedance? a. (37.5 + j150) Ω c. (12.5 + j50) Ω b. (12.5 – j2,450) Ω d. (75.5 – j2,450) Ω 315. Combination of switch and fuse. a. relay c. fuse cut – out b. circuit breaker d. safety switch 316. The phase b voltage and the phase b current of a balanced 3 phase system are: V = 220 sin (ωt + 210°) and I = 10 sin (ωt - 180°). What is the power of the system? a. 3,300 W c. 1,905 W b. 5,716 W d. 3,810 W 317. Three similar coils, when connected in delta to a 3 phase, three wire, 400 volt, 50 Hz supply, take a line current of 7 A at a p.f. of 0.8 lagging. If the coils are now connected in star to the same supply, calculate the line current and total power. a. 2.33 A, 3,879 W c. 7 A, 1,293 W b. 7 A, 3,879 W d. 2.33 A, 1,293 W 42 318. Calculate the error in the ammeter which reads 3.25 A in a circuit having a series standard resistance of 0.01 Ω, the potential difference measured across this standard resistance being 0.035 V. a. 7.7% c. 6.7% b. 7.1% d. 5.1% 319. Estimate the distance over which a load of 15,000 kW at 0.85 p.f. can be delivered by a three – phase transmission line having conductors of steel – cored aluminum each of resistance 0.56 Ω/km. The potential difference at the receiving end is to be 132 kV and the loss in transmission is not to exceed 7.5%. a. 122 km c. 142 km b. 110 km d. 150 km 320. An iron ring, 100 cm mean circumference, is made from an iron rod of round cross – section of 10 cm2. It is wound with 200 turns. What current would be necessary to produce a flux of 1 mWb. Relative permeability of iron = 500. a. 976 A c. 796 A b. 697 A d. 769 A 321. The force between two wires carrying currents in opposite directions is 20.4 kg/m when they are placed with their axes 5 cm apart. Calculate the current in one conductor when current flowing through the other conductor is 5,000 A. a. 1,000 A c. 1,500 A b. 10,000 A d. 5,000 A 322. Two positive point charges 12 x 10-10 coulomb and 8 x 10-10 coulomb are placed 10 cm apart. Find the work done in bringing the two charges 4 cm closer. a. 57.6 x 10-8 J c. 144 x 10-8 J b. 14.4 x 10-8 J d. 5.76 x 10-8 J 323. What is the resonant frequency of a circuit when L is 50 microhenrys and C is 40 picofarads are in parallel? a. 7.96 MHz c. 3.56 MHz b. 79.6 MHz d. 1.78 MHz 324. Which relay is used for feeders? a. MHO relay c. Merz price protection b. Translay relay d. Buchholz relay 43 325. A two branch parallel circuit with one branch of R = 50 ohms and a single unknown element in the other branch has the following applied voltage and the total current: v = 100 cos(1500t + 45°) volts it = 12 sin (1500t + 135°) amperes Find the unknown element. a. R = 8.33 Ω c. L = 10 H b. R = 10 Ω d. L = 8.33 H 326. The following information is given for two transformers connected in parallel and delivering a total load of 300 kVA: Transformer1 Transformer2 Rating = 150kVA Rating = 250kVA 6,900/230 volts 6,900/230 volts Ze – p1 = 9.4 Ω Ze – p2 = 5.8 Ω Calculate the load current supplied by each transformer. a. 26.9 A, 16.6 A c. 734 A, 1190 A b. 21.7 A, 36.2 A d. 24.5 A, 39.7 A 327. A 3 phase, 11 kV transmission line 10km long delivers 200 kW load at 0.8 lagging power factor. The resistance of the line is 0.9 Ω per km per phase. What is the percentage power loss in the line assuming 11 kV voltage at the receiving end. a. 1.27% c. 4.27% b. 3.27% d. 2.27% 328. Fusion energy is produced when a. chemical compounds combined b. fuel burns c. nuclear particles divides d. nuclear particles combined 329. Given Y – connected impedances Za = (2 + j2) Ω, Zb = (5 – j10) Ω, and Zc = (5 + j10) Ω. Find the equivalent delta impedance Zbc. a. (41.22 + j31.23) Ω c. (30 – j10) Ω b. (41.22 – j31.23) Ω d. (-10 + j30) Ω 330. One watt – second is also equal to which one? a. 980 dynes – cm c. 1 erg – second b. 1 joule d. 3 gram – calorie 44 331. A 115 kV line has a horizontal configuration. The distance between adjacent conductors is 9 ft. What is the geometric mean distance of the line? a. 9 ft c. 11.34 ft b. 12 ft d. 18 ft 332. The total capacitance of two capacitors is 0.03 µF when joined in series and 0.16 µF when connected in parallel. Find the capacitance of each capacitor. a. 0.12 µF, 0.04 µF c. 0.03 µF, 0.08 µF b. 0.24 µF, 0.08 µF d. 0.06 µF, 0.16 µF 333. A hydroelectric plant generates 100 MW at an available head of 200 m and an overall efficiency of 75%. What quantity of water in cubic per second is required? a. 1,200 c. 26 b. 122 d. 68 334. The illumination of a room is being designed. The illumination intensity required is 50 footcandles. The maintenance factor is 70% and coefficient of utilization is 60%. If the room is 20 ft by 15 ft, what is the total required lumens output of the lamp? a. 35,000 lumens c. 6,300 lumens b. 10,500 lumens d. 12,800 lumens 335. One kW is equal to ___ ft-lb/sec. a. 1,356 c. 1,055 b. 738 d. 550 336. A battery produces a current of 0.6 A when the external resistance is 2 Ω and 0.2 A when the external resistance is 12 Ω. Find the emf of the battery. a. 3 V c. 9 V b. 6 V d. 12 V 337. An open delta bank delivers a balanced three – phase load of 60 kVA at 460 volts. What current flows in the secondary of each transformer? a. 65.2 A c. 150.6 A b. 130.4 A d. 75.3 A 45 338. The flux density emanating from a pole of a generator is 20,000 gauss. A conductor one meter long cuts the flux perpendicularly at a speed of 40 m per second. What voltage is developed? a. 800 volts c. 230 volts b. 80 volts d. 8 volts 339. The capacitive reactance of a 40 km 34.5 kV line is 90,000 ohms per km. What is the total capacitive reactance of the line? a. 2,250 ohms c. 6,750 ohms 7 b. 1.08 x 10 ohms d. 3.6 x 106 ohms 340. Two voltage generators are in series. The voltages being generated are Vab = 50 sin (ωt - 30°) and Vbc = 100 sin (ωt + 60°). What is the output voltage Vac? a. 111.83 cis 33.5° c. 145.5 cis 50.1° b. 50 cis 30° d. 150 cis 30° 341. A lead – acid battery having a 100 A capacity is 25% charged. After being charged at 10A for 5 hours, it will be approximately ___ charged. a. 1/2 c. fully b. 3/4 d. over 342. A current of 1 ampere passes through a relay coil of 500 turns. What is the mmf? a. 628 gilberts c. 9,425 gilberts b. 943 gilberts d. 595 gilberts 343. The illumination of a room is being designed from the following data: Room length = 40 ft. Required foot – candle = 200 Room width = 24 ft Lumens per lamp = 3,300 Coefficient of utilization = 0.60 No. of rows = 5 Maintenance factor = 0.70 What is the number of lamps per row? a. 40 c. 28 b. 35 d. 140 344. What is the tesla a unit of? a. permittivity c. permeance b. capacitance d. magnetic induction 46 345. A coil having and inductance of 0.05 H and resistance of 10 ohms is connected in series with a 25 µF capacitor across a 220 V ac source. What is the resonance frequency of the circuit? a. 77.2 Hz c. 60 Hz b. 135.2 Hz d. 142.4 Hz 346. Two – wattmeter method is applied to a 3 phase motor running at full – load. Two wattmeters indicate 85.5 kW and 34.7 kW, respectively. What is the operating power factor of the motor? a. 87.45% c. 80.69% b. 89.49% d. 94.76% 347. A transmission line consists of two solid aluminum conductors having a radius of 2.5 cm and separated on centers by a distance of 3.6 m. Find the total line inductance in millihenrys per meter. a. 2.09 x 10-3 c. 0.0209 -3 b. 1.044 x 10 d. 0.0104 348. If output power of a radio receiver is doubled, its volume is increased by _____ db. a. 2 c. 1 b. 3 d. -3 349. Which of the following methods is used to start a synchronous motor? a. resistance starter in the armature circuit b. damper winding c. star – delta starter d. damper winding in conjunction with star – delta starter 350. The power factor of an alternator is determined by its ______. a. speed c. excitation b. load d. prime mover 351. A three – phase induction motor has a nameplate speed of 1,720 rpm. What is the rotor frequency? a. 4.44 Hz c. 1.8 Hz b. 2.7 Hz d. 5 Hz 47 352. A 40 microfarad capacitor is connected in parallel with 40 ohm resistor. What power is drawn when source voltage is V = 220 sin ωt volts? a. 1825 watts c. 1210 watts b. 1010 watts d. 1620 watts 353. The percentage overloading of two 20 kVA transformers when supplying a balanced 3 – phase load of 40 kVA in a V – V bank is ___ percent. a. 15.5 c. 73.2 b. 57.7 d. 33.3 354. A 3 phase, 3 wire feeder supplies an industrial plant with the following data: Line voltages: Vab = 2300 V, Vbc = 230240 V Line currents: Ia = 110-36.87 A, Ic =12553.13 A What is the average power factor of the plant? a. 0.89 lagging c. 0.93 leading b. 0.89 leading d. 0.93 lagging 355. A 3 phase, 3 wire transmission line has an impedance per wire of (3 + j7) ohms, the receiving end load is 1,950 kW, 0.65 power factor lagging with line to line voltage of 13,200 volts. Determine the kVAR of the capacitor to be connected at the receiving end to make the p.f. at that end equal to 0.8 lagging at 13,200 volts. a. 1,482 c. 817 b. 2,280 d. 1,464 356. Two 100 watt, 200 volt lamps are connected in series across a 200 volt supply. The total power consumed by each lamp will be ___ watts. a. 25 c. 100 b. 50 d. 200 357. A conductor cuts 1 weber of flux per sec. The average voltage generated in the conductor is _____. a. 108 mV c. 100 mV b. 1000 mV d. 10 V 358. A 0 – 1 mA meter has a sensitivity of a. 1mA c. 1 k b. 1 k /volt d. 1000 A 48 359. For a dc series motor with saturated condition of the field circuit, the torque developed is proportional to a. speed c. Ia2 b. V12 d. Ia 360. A 100 µF capacitor in series w/ a 50 ohm resistance is connected suddenly across a 125 volt dc supply. What is the voltage in the capacitor after 5 msec.? a. 125 V c. 56.4 V b. 120 V d. 79 V 361. The gas inside the inner discharge tube of a sodium vapor lamp is a. argon c. nitrogen b. neon d. helium 362. The maximum efficiency of a 100 kVA transformer having iron loss of 900 watts and full – load copper loss of 1600 watts occurs at ___ kVA. a. 56.3 c. 75 b. 133.3 d. 177.7 363. In a 4 - pole, 35 slot, dc armature, 180 electrical degree coil span will be obtained when coils occupy ___ slots. a. 1 and 10 c. 2 and 11 b. 1 and 9 d. 3 and 13 364. The transients w/c are produced due to sudden but energetic changes from one steady state of a circuit to another are called ____ transients. a. initiation c. transition b. relaxation d. subsidence 365. A 13.8 kV/440 V, 50 kVA single phase transformer has a leakage reactance of 300 ohms referred to the 13.8 kV side. Determine the per unit value of the leakage reactance for the low – voltage base. a. 0.305 c. 0.097 b. 0.0305 d. 0.079 366. While describing the sheath of a cable, the abbreviation XLPE means ______ polyethylene. a. cross – layer c. cross – linked b. external – layer d. extra – long 49 367. Two capacitors of 0.1 µF, 250 V and 0.2 µF, 500 V are connected in series. What is the maximum voltage that can be applied across the combination? a. 375 c. 750 b. 250 d. 500 368. A dc shunt motor draws an armature current of 98.16 A at 120 V. What is the hp output of the motor if the armature effective resistance is 0.06 ? a. 15.8 c. 7.5 b. 22 d. 15 369. A non sinusoidal emf having the equation v = 141.4 sin (ωt - 60) – 56.6 sin (ωt - 30) + 35.4 sin (5ωt - 90) is impressed upon a circuit. If the current has the equation I = 28.3 sin (ωt - 30) + 17 sin (3ωt - 90), calculate the power factor of the circuit. a. 0.857 c. 0.785 b. 0.578 d. 0.958 370. A diesel power plant has an overall efficiency of 30%. If the calorific value of diesel is 18,000 BTU/1b and cost Php6.00 per liter, how much is the fuel cost of production per kwhr of energy? Take the density of diesel as 900 grams per liter. a. Php1.91/kW-hr c. Php2.12/kW-hr b. Php1.85/kW-hr d. Php2.45/kW-hr 371. Two single phase transformers operate in parallel. Transformer 1 is rated 100 kVA with 4% reactance while transformer 2 is rated 75 kVA with 3% reactance. The transformers have secondary voltages of 220 volts and same voltage ratio. If the common load is 125kva at 80% p.f. lagging, determine the kVA sharing of each transformer. a. 71.43 kVA & 53.57 kVA c. 62.5 kVA & 62.5 kVA b. 75 kVA & 50 kVA d. 82.5 kVA & 42.5 kVA 372. In a 13.8 kV, 10 MVA base three phase system a phase to phase fault occurs. If the thevenin‟s equivalent impedance of the system is 2.63%, what is the magnitude of the fault current? a. 13,800 A c. 27,600 A b. 15,900 A d. 7,970 A 50 373. The sequence components of phase a current are: Ia = 0 Ia1 = (90 + j5.78) A Ia2 = (10 - j5.78) A Determine the phase C current. a. 91.61131 A c. 100120 A b. 1000 A d. 91.61251 A 374. The CT ratio and PT ratio used to protect a line are 240 and 2000, respectively. If the impedance of each line is 10 , what is the relay impedance to protect the line from fault? a. 83.33  c. 48,000  b. 1.2  d. 12  375. What is the most probable per unit transient reactance for an alternator rated 100 MW? a. 0.02 c. 1.0 b. 0.30 d. 0.1 376. What should be the kV rating of a surge arrester to be used for an 11 kV ungrounded system? a. 18 kV c. 12 kV b. 16 kV d. 9 kV 377. A three – phase, 4 – pole induction motor with open – circuited rotor is connected to a 400 V, 50 Hz, three – phase supply. The motor will run at ____ rpm. a. 1500 c. 1450 b. 1480 d. 0 378. What is the self geometric mean distance of a 3 – strand bundle made of ACSR Rail conductors with 45 cm between conductors? The GMR of ACSR Rail is 0.0386 ft. a. 0.4832 ft c. 0.3842 ft b. 0.2834 ft d. 0.4382 ft 379. A 3 phase balanced system working at 0.9 p.f. lagging has a line loss of 3,600 kW. If p.f. is reduced to 0.6, the line loss would become _____ kW. a. 8,100 c. 5,400 b. 1,600 d. 4,800 51 380. A 55,000 kW thermal power plant of NPC delivers an annual output of 283,000 MWHr with a peak load of 44 MW. The annual load factor of the plant is nearest to a. 0.75 c. 0.76 b. 0.72 d. 0.73 381. For power transformers, the conservator tank is intended to minimize a. heating c. oil slugging b. internal pressure d. breathing 382. A generator rated 15 MVA, 13.2 kV has 8% impedance is connected to a step – up transformer of 20 MVA, 13.8/230 kV for transmission. What is the new per unit impedance using transformer ratings as base value? a. 0.146 c. 0.098 b. 0.102 d. 0.107 383. In a vacuum tube, what is the ratio of a small change in plate voltage to a small change in grid voltage? a. amplification ratio c. current ratio b. voltage ratio d. amplification factor 384. What is the normal indication on a megger when checking insulation? a. one c. middle of scale b. infinity d. zero 385. A flux of 1,500,000 maxwells links a coil having 350 turns. This flux through the coil is decreased to zero at a uniform rate in 0.2 sec. Determine induced emf during this time interval. a. 1 volt c. 26.25 volts b. 857 volts d. 8.57 volts 386. What electric power is required to drive a pump which must raise water 96ft and supply 2,600 gpm? One gallon water weighs 8.3lbs. motor and pump efficiency are 90% and 70%, respectively. a. 46.8 kW c. 29.5 kW b. 74.3 kW d. 60.2 kW 52 387. The winding of a 4 – pole alternator having 36 slots is short by 2 slots. What is the pitch factor? a. 0.9397 c. 0.9566 b. 0.9725 d. 1.0 388. The unit of magnetic field intensity in the CGS system is a. gauss c. ampere – turn per meter b. gilbert d. Oersted 389. What is the work done in moving a 50 C electric charge through a distance of 50cm in the direction of a uniform electric field of 50 kV/m? a. 2.5 joules c. 1.25 joules b. 500 joules d. 125 joules 390. A coil with L = 2 H and R = 362  is connected to a 230 V, 50 Hz supply. Calculate the energy stored when the instantaneous voltage is zero. a. 0.317 J c. 0.151 J b. 0.051 J d. 0 391. A system is consists of three equal resistors connected in delta and is fed from a balanced three –phase supply. By how much power is reduced if one of the resistors is disconnected? a. 33% c. 50% b. 67% d. 25% 392. A round wire has 250,000 CM. Find its diameter in inches. a. 1/2 c. 0.16 b. 1/4 d. 0.08 393. One horsepower is equal to _____.