EE Take Home Exam 1 April 2025 PDF

EXCEL FIRST REVIEW AND TRAINING CENTER, INC. Cebu: JRT Bldg. Imus Ave, Cebu City | Manila: CMFFI Bldg. R. Papa St. Sampaloc Electrical Engineering Baguio: 4th Fl. De Guzman Bldg., Legarda Road | SPLE: GCC and Singapore T...

EXCEL FIRST REVIEW AND TRAINING CENTER, INC. Cebu: JRT Bldg. Imus Ave, Cebu City | Manila: CMFFI Bldg. R. Papa St. Sampaloc Electrical Engineering Baguio: 4th Fl. De Guzman Bldg., Legarda Road | SPLE: GCC and Singapore Take Home Exam 1 1. If load on a dc shunt motor is 9. The primary and secondary windings 15. No-load test on a transformer is increased, its speed is decreased due of an ordinary 2-winding transformer carried out to determine ____. primarily to: always have _____. A. copper loss A. increase in its flux A. different number of turns B. magnetizing current B. decrease in back emf * B. same size of copper wire C. magnetizing current and no-load C. increase in armature current C. a common magnetic circuit * loss * D. increase in brush drop D. separate magnetic circuits D. efficiency of the transformer 2. A transformer transforms ____. 10. In a transformer, the leakage flux of 16. The main purpose of performing each winding is proportional to the open circuit test on a transformer is A. frequency current in that winding because ____. to measure its ____. B. voltage C. current A. Ohm’s law applies to magnetic A. Cu loss D. voltage and current * circuits B. core loss * B. leakage paths do not saturate * C. total loss 3. Which of the following is not a basic C. the two windings are electrically D. insulation resistance element of a transformer? isolated D. mutual flux is confined to the core 17. During short-circuit test, the iron loss A. Core of a transformer is negligible B. Primary winding 11. In relation to a transformer, the ratio because _____. C. Secondary winding 20:1 indicates that ____. D. Mutual flux * A. the entire input is just sufficient A. there are 20 turns on primary, one to meet Cu losses only 4. In an ideal transformer ____. turn on secondary B. flux produced is a small fraction B. secondary voltage is 1/20th of of the normal flux * A. windings have no resistance primary voltage C. iron core becomes fully B. core has no losses C. primary current is 20 times greater saturated C. core has infinite permeability than the secondary current D. supply frequency is held D. All of the above * D. for every 20 turns on primary, constant there is one turn on secondary * 5. The main purpose of using core in a 18. In operating a 400 Hz transformer at transformer is to _____. 12. In performing the short circuit test of 50 Hz ____. a transformer ____. A. decrease iron losses A. only voltage is reduced in the B. prevent eddy current loss A. high voltage side is usually short same proportion as the C. eliminate magnetic hysteresis circuited frequency D. decrease reluctance of the B. low voltage side is usually short B. only kVA rating is reduced in the common magnetic circuit * circuited * same proportion as the C. any side is short circuited with frequency * 6. Transformer cores are laminated in preference C. both voltage and kVA rating are order to ____. D. None of the above reduced in the same proportion as the frequency A. simplify its construction 13. A transformer has negative voltage D. None of the above B. minimize eddy current loss * regulation when its load power factor C. reduce cost is _____. 19. If the load current and flux of a dc D. reduce hysteresis loss motor are held constant and voltage A. zero applied across its armature is 7. The primary and secondary induced B. unity increased by 10 percent, its speed emf’s E1 and E2 in a two-winding C. leading * will ______. transformer are always ____. D. lagging A. decrease by about 10 percent A. equal in magnitude 14. The primary reason why open-circuit B. remain unchanged B. antiphase with each other test is performed on the low-voltage C. increase by about 10 percent * C. in-phase with each other * winding of the transformer is that it D. increase by 20 percent D. determined by load on ____. transformer secondary 20. If the pole flux of a dc motor A. draws sufficiently large on-load approached zero, its speed will 8. A step-up transformer increases current for convenient reading * _____. _____. B. requires least voltage to perform the test A. approach zero A. voltage * C. needs minimum power input B. approach infinity * B. current D. involves less core loss C. no change due to corresponding C. power change in back emf D. frequency Website: www.excelreviewcenter.com.ph Facebook: Excel Review Center Cellphones: Smart: 0919 822 5048 Globe: 09173239235  EXCEL FIRST REVIEW AND TRAINING CENTER, INC. Cebu: JRT Bldg. Imus Ave, Cebu City | Manila: CMFFI Bldg. R. Papa St. Sampaloc Electrical Engineering Baguio: 4th Fl. De Guzman Bldg., Legarda Road | SPLE: GCC and Singapore Take Home Exam 1 D. approach a stable value C. tripled 34. When a pure inductive coil is fed by a somewhere between zero and D. quadrupled complex voltage wave, its current infinity wave _____. 28. In a simple high-pass RL circuit, the 21. The decibel is a measure of phase difference between the output A. has larger harmonic content ____________. and input voltages at the cutoff B. is more distorted frequency is _____ degrees. C. is identical with voltage wave A. power D. shows less distortion * B. voltage A. -90 C. current B. -45 35. A complex voltage wave is applied D. power level * C. 45 * across a pure capacitor. As D. 90 compared to the fundamental 22. When the output voltage level of a voltage, the reactance offered by the filter decreases by -3 dB, its absolute 29. When two simple low-pass filters capacitor to the third harmonic value changes by a factor of having same values of R and C are voltage would be ____. cascaded, the combined filter will A. 20.5 have a roll-off of _____ dB/decade. A. nine times B. 1 / 20.5 * B. three times C. 2 A. -20 C. one-third * D. ½ B. -12 D. one-ninth C. -40 * 23. The frequency corresponding to half- D. -36 36. Which of the following harmonic power point on the response curve of voltage components in a 3-phase a filter is known as _________. 30. The output of a filter drops from 10 to system would be in phase with each 5 V as the frequency is increased other? A. cutoff * from 1 to 2 kHz. The dB change in the B. upper output voltage is ____. A. 3rd, 9th, 14th, etc C. lower B. 7th, 13th, 19th, etc D. roll-off A. -3 dB/decade C. 5th, 11th, 17th, etc B. -6 dB/octave * D. 2nd, 4th, 6th, etc * 24. In a low-pass filter, the cutoff C. 6 dB/octave frequency is represented by the point D. -3 dB/octave 37. A given function f(t) can be where the output voltage is reduced represented by a Fourier series if it to _____ percent of the input voltage. 31. Non-sinusoidal waveforms are made ___. up of _____. A. 50 A. is periodic B. 70.7 * A. different sinusoidal waveforms * B. is single valued C. 63.2 B. fundamental and even C. has a finite number of maxima D. 33.3 harmonics and minima in any one period C. fundamental and odd harmonics D. All of the above * 25. In an RL low-pass filter, an D. even and odd harmonics only attenuation of -12 dB/octave 38. In a Fourier series expansion of a corresponds to ______ dB/decade. 32. The positive and negative halves of a periodic function, the coefficient ao complex wave are symmetrical when represents its _____. A. -6 ______. B. -12 A. net area per cycle C. -20 A. it contains even harmonics B. DC value * D. -40 * B. phase difference between even C. average value over half cycle harmonics and D. average ac value per cycle 26. A network which attenuate a single fundamental is 0 or  band of frequencies and allows C. it contains odd harmonics * 39. If the average value of a periodic those on either side to pass through D. phase difference between even function over one period is zero and is called a _________ filter. harmonics and fundamental is it consists of only odd harmonics either π/2 or 3/2 then it must be possessing _________ A. low-pass symmetry. B. high-pass 33. In a 3-phase system, ___the C. bandstop * harmonic has negative phase A. half-wave * D. bandpass sequence of RBY. B. even quarter-wave C. odd quarter-wave 27. In a simple high-pass RC filter, if the A. 9 D. odd value of capacitance is doubled, the B. 13 cutoff frequency is ____. C. 5* 40. A periodic function has zero average D. 15 value over a cycle and its Fourier A. doubled series consists of only odd cosine B. halved * Website: www.excelreviewcenter.com.ph Facebook: Excel Review Center Cellphones: Smart: 0919 822 5048 Globe: 09173239235  EXCEL FIRST REVIEW AND TRAINING CENTER, INC. Cebu: JRT Bldg. Imus Ave, Cebu City | Manila: CMFFI Bldg. R. Papa St. Sampaloc Electrical Engineering Baguio: 4th Fl. De Guzman Bldg., Legarda Road | SPLE: GCC and Singapore Take Home Exam 1 terms. What is the symmetry another are called ________ B. 1250 possessed by this function? transients. C. 1333 * D. 1000 A. Even A. initiation B. Odd B. transition * 54. 1 kWh of energy equals nearly _____. C. Even quarter-wave * C. relaxation D. Odd quarter-wave D. subsidence A. 1000W B. 860 kcal * 41. A periodic waveform possessing half- 48. In an R-L circuit connected to an C. 4186 J wave symmetry has no ____. alternating sinusoidal voltage, size of D. 735.5 W transient current primarily depends A. even harmonics * on ____. 55. 1 kWh of electric energy equals B. odd harmonics _____. C. sine terms A. the instant in the voltage cycle at D. cosine terms which circuit is A. 3600 J closed * B. 860 kcal * 42. The Fourier series of a waveform B. the peak value of steady-state C. 3600 W possessing even quarter-wave current D. 4186 J symmetry has only ____. C. the circuit impedance D. the voltage frequency 56. A capacitor consists of two _____. A. even harmonics B. odd cosine terms * 49. Double-energy transients are A. insulation separated by C. odd sine terms produced in circuits consisting of dielectric D. Both B and C _____. B. conductors separated by dielectric * 43. The Fourier series of a waveform A. two or more resistors C. ceramic plates and one mica possessing odd quarter-wave B. resistance and inductance disc symmetry contains only _____. C. resistance and capacitance D. silver-coated insulators D. resistance, inductance and A. even harmonics capacitance * 57. The capacitance of a capacitor is not B. odd cosine terms influenced by ____. C. odd sine terms * 50. The transient current in a loss-free L- D. None of the above C circuit when excited from an ac A. plate thickness * source is a/an _______ sine wave. B. plate area 44. Transient disturbance is produced in C. plate separation a circuit whenever _____. A. overdamped D. nature of the dielectric B. undamped * A. it is suddenly connected or C. under damped 58. What is the unit of absolute disconnected from the D. critically damped permittivity of a medium? supply B. it is shorted 51. If a 220 V heater us used on 110 V A. Joule/coulomb C. its applied voltage is changed supply, heat produced by it will be B. Newton-meter suddenly ____ as much. C. Farad/meter * D. All of the above * D. Farad/coulomb A. one-half 45. There are no transients in pure B. twice 59. What is the unit of electric intensity? resistive circuits because they _____. C. one-fourth * D. four times A. Joule/coulomb A. offer high resistance B. Newton/coulomb B. obey Ohm’s law 52. For a given line voltage, four heating C. Volt/meter C. have no stored energy * coils will produce maximum heat D. Both B and C * D. are linear circuits when connected ____. 60. Inside a conducting sphere, 46. Transient currents in electrical A. all in parallel * _________ remains constant circuit are associated with ____. B. all in series C. with two parallel pairs in series A. electric flux A. inductors D. one pair in parallel with the other B. electric intensity B. capacitors two in series C. charge C. resistors D. potential * D. Both A and B * 53. The electric energy required to raise the temperature of a given amount of 61. What is the SI unit for electric 47. The transients that are produced due water is 1000 kWh. If heat losses are intensity? to sudden but energetic changes 25%, the total heating energy from one steady state of a circuit to required is _____ kWh. A. N/m B. V/m A. 1500 Website: www.excelreviewcenter.com.ph Facebook: Excel Review Center Cellphones: Smart: 0919 822 5048 Globe: 09173239235  EXCEL FIRST REVIEW AND TRAINING CENTER, INC. Cebu: JRT Bldg. Imus Ave, Cebu City | Manila: CMFFI Bldg. R. Papa St. Sampaloc Electrical Engineering Baguio: 4th Fl. De Guzman Bldg., Legarda Road | SPLE: GCC and Singapore Take Home Exam 1 C. N/C 69. The ratio of Ah efficiency to Wh B. smaller quantity of electrolyte D. Either B or C * efficiency of a lead-acid cell is ____. used C. higher internal resistance * 62. Which of the following is zero inside A. always less than one D. compactness a charged conducting sphere? B. just one C. always greater than one * 77. Trickle charging of a storage battery A. Potential D. Either A or B helps to ____. B. Electric intensity C. Both A and B * 70. The capacity of a cell is measured in A. prevent sulphation D. Both B and C ____. B. keep it fresh and fully charged * C. maintain proper electrolyte level 63. In practice, why earth is chosen as a A. Watt-hours D. increase its reserve capacity place of zero electric potential? B. Watts C. Amperes 78. The sediment which accumulates at A. Because it is non-conducting. D. Ampere-hours * the bottom of a lead-acid battery B. Because it is easily available. consists largely of ____. C. Because it keeps losing and 71. The capacity of a lead-acid cell does gaining electric charge every not depend on its ___. A. lead peroxide day. B. lead-sulphate D. Because it has almost constant A. rate of charge * C. antimony-lead alloy * potential. * B. rate of discharge D. graphite C. temperature 64. What is the relative permeability of D. quantity of active material 79. Floating battery systems are widely vacuum? used for ____. 72. As compared to constant-current A. 4π x 10-7 H/m system, the constant-voltage system A. power stations B. 1 H/m of charging a lead-acid cell has the B. emergency lighting C. 1* advantage of _____. C. telephone exchange installation D. ¼π D. All of the above * A. avoiding excessive gassing 65. What is the unit of magnetic flux? B. reducing time of charging 80. Any charge given to the battery when C. increasing cell capacity taken off the vehicle is called ____ A. Weber * D. Both B and C * charge. B. Tesla C. Ampere-turn 73. Sulphation in a lead-acid battery A. bench * D. Coulomb occurs due to ____. B. float C. step 66. Which is the wrong statement? The A. trickle charging D. trickle magnetizing force at the center of a B. incomplete charging * circular coil varies ____. C. heavy discharging 81. An ac current given by i D. fast charging =14.14sin(ωt+π/6) has an rms value A. directly as the number of its of ____ amperes. turns * 74. What are the active materials of a B. directly as the current nickel-iron battery? A. 10 * C. directly as its radius B. 14.14 D. inversely as its radius A. Nickel hydroxide C. 1.96 B. Powdered iron and its oxides D. 7.07 67. Active materials of lead-acid cells C. 21% solution of caustic potash are _____. D. All of the above * 82. An ac current given by i =14.14sin(ωt+π/6) has phase of A. lead peroxide 75. During charging and discharging of a _____ degrees. B. sponge lead nickel-iron cell: C. dilute sulfuric acid A. 180 D. All of the above * A. Its emf remains constant. B. 30 * B. Water is neither formed nor C. -30 68. Which of the following is true during absorbed. * D. 210 the charging of a lead-acid cell? C. Corrosive fumes are produced. D. Nickel hydroxide remains 83. The rms value of a half-wave rectified A. Its cathode becomes dark unsplit. current is 10A, its value for full-wave chocolate brown in color. rectification would be _____ B. Its voltage increases. * 76. As compared to a lead-acid cell, the amperes. C. It gives out energy. efficiency of a nickel-iron cell is less D. Its voltage decreases. due to its ____. A. 20 B. 14.14 * A. lower emf C. 20/π D. 40/π Website: www.excelreviewcenter.com.ph Facebook: Excel Review Center Cellphones: Smart: 0919 822 5048 Globe: 09173239235  EXCEL FIRST REVIEW AND TRAINING CENTER, INC. Cebu: JRT Bldg. Imus Ave, Cebu City | Manila: CMFFI Bldg. R. Papa St. Sampaloc Electrical Engineering Baguio: 4th Fl. De Guzman Bldg., Legarda Road | SPLE: GCC and Singapore Take Home Exam 1 84. The rms value of sinusoidal ac C. comes to the ground state 99. Doping materials are called current is equal to its value at an D. is completely removed * impurities because they ____. angle of ____ degree. 92. The maximum number of electrons A. decrease the number of charge A. 60 which the M-shell of an atom can carriers B. 45 * contain is _____. B. change the chemical properties C. 30 of semiconductors D. 90 A. 32 C. make semiconductors less than B. 8 100 percent pure 85. As sine wave has a frequency of 50 C. 18 * D. alter the crystal structures of the Hz. Its angular frequency is ____ D. 50 pure semiconductors* radian/second. 93. Electron distribution of an Si atom is 100. The conjugate of (-a+jb) is ____. A. 50/ ____. B. 50/2 A. (a-jb) C. 50 A. 2, 10, 2 B. (-a-jb) * D. 100 * B. 2, 8, 4 * C. (a+jb) C. 2, 7, 5 D. (jb-a) 86. The reactance offered by a capacitor D. 2, 4, 8 to alternating current of frequency 50 * * * END * * * Hz is 10 ohms. If frequency is 94. Semiconductor materials have ____ increased to 100 Hz, reactance bonds. becomes ____ ohm. A. ionic A. 20 B. covalent * B. 5* C. mutual C. 2.5 D. metallic D. 40 95. The maximum number of electrons 87. The symbol j represents which the valence shell of an atom counterclockwise rotation of a vector can have is ____. through ____ degrees. A. 6 A. 180 B. 8* B. 90 * C. 18 C. 360 D. 2 D. 270 96. Silicon has Z = 14. Its outermost orbit 88. The operator j has a value of ____. is ____. A. +1 A. partially filled B. -1 B. half filled * C. -10.5 * C. completely occupied D. +10.5 D. empty 89. What is the p.f. of an R-C circuit? 97. Major part of the current in an intrinsic semiconductor is due to A. Often zero ____. B. Between zero and 1 * C. Always unity A. conduction-band electrons * D. Between zero and -1 B. valence-band electrons C. holes in the valence band 90. The total energy of a revolving D. thermally-generated electron electron in an atom can ____. 98. Conduction electrons have more A. have any value above zero mobility than holes because they B. never be positive * _____. C. never be negative D. not be calculated A. are lighter B. experience collisions less 91. An atom is said to be ionized when frequently any one of its orbiting electron _____. C. have negative charge D. need less energy to move them * A. jumps from one orbit to another B. is raised to a higher orbit Website: www.excelreviewcenter.com.ph Facebook: Excel Review Center Cellphones: Smart: 0919 822 5048 Globe: 09173239235