Electrical Engineering Review Center Past Paper PDF

## ROJAS ELECTRICAL ENGINEERING REVIEW CENTER **2nd Floor, Yap Building, 35 M. Velez St, Barangay Guadalupe, Cebu City** **EE-1** **LASTNAME** _FIRSTNAME_ **CONSTANT PRACTICE MAKES YOU PERFECT** 1. A light bulb rated 150 W at 240 V is connected to a 120 V supply. Find the current that flows....

## ROJAS ELECTRICAL ENGINEERING REVIEW CENTER **2nd Floor, Yap Building, 35 M. Velez St, Barangay Guadalupe, Cebu City** **EE-1** **LASTNAME** _FIRSTNAME_ **CONSTANT PRACTICE MAKES YOU PERFECT** 1. A light bulb rated 150 W at 240 V is connected to a 120 V supply. Find the current that flows. * A. 0.63 A * B. 1.88 A * C. 1.25 A * D. 0.31A 2. Find the energy used by a toaster with a resistance of 12 Ω, which is operated at 120 V for 10 s. * A. 10 kJ * B. 14.4 kJ * C. 12 kJ * D. 17.28 kJ 3. The term electric pressure _of_ a circuit refers to the _<ins>of_ a circuit_. * A. voltage * B. resistance * C. current * D. power drawn 4. A nichrome wire used as a heater coil has a resistance of 2 Ω/m. For a heater rated 1 kW at 200 V, find the length of the wire. * A. 80 m * B. 40 m * C. 60 m * D. 20 m 5. The resistance of a copper wire to the flow of current through it * A. decreases as the diameter of the _wire_ decreases * B. increases as the diameter of the _wire_ increases * C. decreases as the length if the _wire_ increases * D. increases as the length of the _wire_ increases 6. The work done across two points having potential difference of 20 V is 60 J. Find the charge flowing between the two points. * A. 3 C * B. 1200 C * C. 1/3 C * D. 6 C 7. Joule found out that the heat produced in a current carrying conductor is proportional to the * A. current * B. square of resistance * C. square of current * D. inverse of time 8. The resistance of a given wire 200 m long is 21 Ω. If its diameter is 0.44 mm, find its specific resistance. * A. 1.2 x 10-8 Ω-m * B. 1.2 109 Ω-m * C. 1.6 x 10-8 Ω-m * D. 1.6 x 109 Ω-m 9. A heating element supplies 300 kJ in 50 minutes. Find the pd across the element when current is 2 A. * A. 36 V * B. 50 V * C. 30 V * D. 45 V 10. The SI unit of specific resistance is called * A. mho * B. ohm-m * C. ohm * D. ohm/m 11. A conductor, 40 m long and cross-sectional area of 1 mm² has a resistance of 12 Ω. Find the conductivity of the conductor. * A. 3.33 MS/m * B. 6.67 MS/m * C. 0.333 MS/m * D. 0.667 MS/m 12. The voltage applied across the circuit will act as a _<ins>that causes current to flow_ that causes current to flow. * A. switch * B. heat * C. medium * D. force 13. A lamp of 800 Ω resistance is connected across a 200 V supply. Find the current flowing in the lamp. * A. 4 A * B. 50 A * C. 0.25 A * D. 3.2 A 14. Of the ways in producing emf, which method is used the least? * A. Pressure * B. Chemical reaction * C. Solar * D. Friction 15. A wire of length 1 m has a resistance of 2 Ω. Find the resistance of a second wire, whose specific resistance is double the first, if the length of the wire is 3 m and the diameter is double of the first. * A. 3 Ω * B. 4 Ω * C. 6 Ω * D. 8 Ω 16. Find the ohmic resistance of a carbon resistor color coded with, yellow, orange, orange and silver. * A. 4.3 ΜΩ ± 10% * B. 430 Ω ± 10% * C. 430 ΚΩ ± 10% * D. 43 ΚΩ ± 10% 17. A negatively charged body has * A. deficit of neutrons * B. excess of neutrons * C. excess of electrons * D. deficit of electrons 18. A length of wire has a resistance of 6 Ω. Find the resistance of a wire of the same material three times as long and twice the cross-sectional area. * A. 36 Ω * B. 12 Ω * C. 9 Ω * D. 1 Ω 19. Find the atomic mass number of an atom with 9 protons, 11 neutrons and 9 electrons. * A. 9 * B. 20 * C. 18 * D. 29 20. An electrical insulator is a material * A. containing no electrons * B. through which electrons do not flow easily * C. that has more electrons than protons on its surface * D. cannot be a pure chemical element 21. Find the potential difference between the ends of a wire of resistance 5 Ω if 720 C passes through it per minute. * A. 60 V * B. 2.4 V * C. 144 V * D. 12 V 22. Find the work done by a power source with a potential difference of 3 kV that delivers a current of 1 A for 1 minute. * A. 150 kJ * B. 160 kJ * C. 170 kJ * D. 180 kJ 23. The presence of electric current is made known by * A. flashing * B. cracking * C. effects produced * D. electric shock 24. Find the resistivity of a wire used as a variable 39-Ω resistance if the wire has a length of 266 ft and a diameter of 0.0226 mils. * A. 75 Ω-CM/ft * B. 90 Ω-CM/ft * C. 102 Ω-CM/ft * D. 88 Ω-CM/ft 25. The resistance of a conductor varies directly as its * A. length * B. radius * C. diameter * D. cross-sectional area 26. A copper coil has a resistance of 162 Ω at 60°C. What is the percent decrease in resistance at 20°C? Temperature coefficient of resistance is 0.00393/°C at 20°C. * A. 13.58% * B. 14.16% * C. 12.37% * D. 15.71% 27. A substance that cannot be decomposed further into simpler substances during ordinary chemical reactions. * A. Atom * B. Mixture * C. Molecule * D. Element 28. How much energy does a 5 hp motor deliver in 2 hours? * A. 6.72 MJ * B. 26.9 MJ * C. 7.46 MJ * D. 34.13 MJ * 29. A fuse wire should be of material that has _<ins>resistivity and melting point_ resistivity and _<ins>melting point_ melting point. * A. low, low * B. high, low * C. high, high * D. low, high 30. A coil of copper wire has a resistance of 6 Ω at a room temperature of 24°C. Find its resistance at 80°C. * A. 74.21 Ω * B. 73.36 Ω * C. 75.43 Ω * D. 76.34 Ω 31. According to Ohm's law, voltage is directly proportional to * A. square of resistance * B. conductance * C. square of current * D. current 32. A 20-m length of a certain wire has a resistance of 15 Ω. Find the length of this wire to have a resistance of 8 Ω. * A. 37.5 m * B. 10.7 m * C. 5.68 m * D. 70.31 m **THE BOARD EXAM IS AN INDIVIDUAL COMPETITION!** **_&lt;1/5&gt;_** **STUDY HARDER, IT WILL BE YOU AGAINST ALL OTHERS** ## ROJAS ELECTRICAL ENGINEERING REVIEW CENTER **2nd Floor, Yap Building, 35 M. Velez St, Barangay Guadalupe, Cebu City** 33. In the color code for carbon resistors, green color represents the number * A. 5 * B. 6 * C. 4 * D. 7 34. A single-core cable has a conductor diameter of 1 cm and an insulation thickness of 0.4 cm. If the specific resistance of insulation is 5 x 1024 Ω-cm, find the insulation resistance for a 2 km length of the cable. * A. 243 ΜΩ * B. 342 ΜΩ * C. 234 ΜΩ * D. 324 ΜΩ 35. Which one of the following quantities is correctly matched to its unit? * A. Power - kW-h * B. Potential difference - J/C * C. Energy - kW * D. Current - A/s 36. An atom has an atomic number of 53 and an atomic mass of 131. Find the number of electrons of the atom. * A. 53 * B. 78 * C. 131 * D. 69 37. A wire of certain length and resistance is drawn out to three times its length without change in volume. The new resistance of the wire becomes _<ins>as much_ as much. * A. 1/9 times * B. 9 times * C. 3 times * D. 1/3 times 38. The effect of electric shock on human body depends on * A. voltage * B. duration of contact * C. current * D. all of these 39. The maximum number of electrons in the M-shell of an atom is * A. 32 electrons * B. 8 electrons * C. 18 electrons * D. 2 electrons 40. The insulation resistance of a 50 km long cable is 1 ΜΩ. Find the insulation resistance for a 100 km length of this cable. * A. 1 ΜΩ * B. 0.5 ΜΩ * C. 2 ΜΩ * D. 0.66 ΜΩ 41. In a particular circuit connection, #18 AWG wire is selected over #22 AWG wire. The reason is that it is having * A. lesser weight * B. higher resistance * C. lesser thickness * D. higher current capacity 42. A conductor has cross sectional area of 1 cm² and a free electron density of 1 x 1024 e/m³. If a drift velocity of 0.015 m/s is attained by the electrons, find the magnitude of the current. * A. 0.24 A * B. 0.27 A * C. 0.21 A * D. 0.32 A 43. The SI unit of charge. * A. Ohm * B. Weber * C. Coulomb * D. Tesla 44. A wire has a resistance of 5 Ω. The wire is further drawn until its length becomes doubled. Find its new resistance. * A. 1.25 Ω * B. 10 Ω * C. 2.5 Ω * D. 20 Ω 45. A semi-conductor has _&lt;ins>valence electrons&gt;_ valence electrons. * A. less than 4 * B. more than 4 * C. exactly 4 * D. no 46. If 5 J of work are done in moving 0.025 C of positive charge from point A to point B, find the difference in potential of the points A and B. * A. 200 V * B. 8000 V * C. 0.125 V * D. 5 mV 47. A kilowatt hour is a unit of * A. charge * B. power * C. current * D. energy 48. A copper wire of area of cross-section 1 mm² is carrying a current of 10 A. If the density of the electrons is 1 x 1028 e/m³, find the drift velocity of the conduction electrons. * A. 5 mm/s * B. 6.67 mm/s * C. 6.25 mm/s * D. 8.33 mm/s 49. A wire carries a steady current of 2 A. Find the charge that passes a cross section in 2 s. * A. 1 C * B. 2 C * C. 1/2 C * D. 4 C 50. The rate at which electrical energy is used may be measured in units * A. watt/second * B. joule * C. watt-second * D. watt 51. Number 00 wire (AWG) has a diameter of 0.3648 inch. Find its cross-sectional area in circular mils. * A. 133,100 CM * B. 125,800 CM * C. 145,200 CM * D. 113,500 CM 52. If the number of valence electrons of an atom _<ins>is less than 4_ is less than 4, the substance is called * A. conductor * B. insulator * C. semiconductor * D. superconductor 53. There are 5 x 1016 free electrons passing a point in a conductor in 20 s. Find the intensity of the current flow. * A. 0.4 mA * B. 0.6 mA * C. 0.2 mA * D. 0.8 mA 54. In a conductor carrying a current we expect the electron drift speed to be * A. much greater than the average electron speed * B. much less than the average electron speed * C. about the same as the average electron speed * D. less than the average electron speed at low temperature and greater than the average electron speed at high temperature 55. A metal plate has a charge of +3 C. If 12.5 x 1018 electrons are added to it, find the net charge on the plate. * A. +5 C * B. -2 C * C. 1 C * D. zero 56. An electrically charged atom is known as * A. a molecule * B. an ion * C. an Isotope * D. a fundamental particle 57. A heater wire of length 50 cm and 1 mm² in cross section carries a current of 2 A when connected across a 2 V cell. Find the specific resistance of the wire. * A. 2 x 106 Ω-m * B. 1 x 106 Ω-m * C. 2 x 10-8 Ω-m * D. 4 x 10-8 Ω-m 58. A positively charged body has * A. deficit of electrons * B. excess of electrons * C. excess of neutrons * D. deficit of neutrons 59. Which resistor will be physically larger in size? * A. 10 Ω, 50 W * B. 1000 Ω, 1/2 W * C. 100 Ω, 10 W * D. 10 ΜΩ, 1 W 60. The resistance of a conductor is 80 Ω at 40°C. Find its resistance at 20°C if the temperature coefficient of resistance is 0.0039/°C at 20°C? * A. 69.38 Ω * B. 77.72 Ω * C. 74.21 Ω * D. 63.92 Ω 61. A car battery supplies 48 J of energy at 12 V over a certain period of time. Find the charge moved during this period. * A. 4 C * B. 576 C * C. 0.25 C * D. 24 C 62. The terminal pd of a battery is less than its emf, * A. under all conditions * B. only when the battery is being charged * C. only when there is no current in the battery * D. only when the battery is being discharged 63. Find the number of electrons that must be removed from a neutral object to leave a net charge of +0.5 µC. * A. 3.125 x 1012 electrons * B. 3.667 x 1012 electrons * C. 3.250 x 1012 electrons * D. 3.333 x 1012 electrons 64. A material has a conductivity of 105 S/m. Find its resistivity. * A. 1 μΩ-m * B. 0.01 Ω-m * C. 0.1 μΩ-m * D. 1 ΜΩ-m **THE BOARD EXAM IS AN INDIVIDUAL COMPETITION!** **_&lt;2/5&gt;_** **STUDY HARDER, IT WILL BE YOU AGAINST ALL OTHERS** ## ROJAS ELECTRICAL ENGINEERING REVIEW CENTER **2nd Floor, Yap Building, 35 M. Velez St, Barangay Guadalupe, Cebu City** 65. Find the insulation resistance of a cable 6437.6 m long and having conductor diameter of 1.5 cm and internal sheath diameter of 3 cm. Specific resistance of insulating material is 6 x 1014 Ω-cm. * A. 103 ΜΩ * B. 110 ΜΩ * C. 106 ΜΩ * D. 114 ΜΩ 66. The drift velocity of electrons is * A. equal to the speed of light * B. larger than the speed of light * C. almost equal to the speed of light * D. very small in comparison to the speed of light 67. An ordinary light bulb is rated 60 W, 120 V. Find its resistance. * A. 2 Ω * B. 240 Ω * C. 30 Ω * D. 0.5 Ω 68. A wire having a diameter of 12 mm and a resistance of 0.3 Ω is drawn to reduced its diameter to 5 mm. Find its new resistance. * A. 1.73 Ω * B. 4.64 Ω * C. 0.72 Ω * D. 9.95 Ω 69. A substance whose molecules consist of dissimilar atoms. * A. Conductor * B. Element * C. Insulator * D. Compound 70. Find the resistance of a copper bus bar if the length is 10 m and the cross-section is a square 4 cm on each side. Use 1.724 μΩ-cm as the resistivity. * A. 110 μΩ * B. 115 μΩ * C. 108 μΩ * D. 118 μΩ 71. The temperature coefficient of resistance of a conductor _&lt;ins>with the rise in temperature&gt;_ with the rise in temperature. * A. increases * B. decreases * C. remains unchanged * D. none of these 72. The N-shell of an atom can have a maximum of _<ins>electrons&gt;_ electrons. * A. 32 electrons * B. 8 electrons * C. 18 electrons * D. 2 electrons 73. A conductor has an area of 40 MCM. What is the diameter of the conductor in inches? * A. 0.141 * B. 0.04 * C. 0.20 * D. 0.063 74. The normal indication on a megger when checking insulation is * A. zero * B. negative value * C. middle in the scale * D. Infinity 75. Find the number of electrons needed to accumulate a total charge of 0.008 C. * A. 4 x 1016 electrons * B. 5 x 1016 electrons * C. 3 x 1016 electrons * D. 2 x 1016 electrons 76. Current flow is electron in _<ins>charge&gt;_ charge. * A. negative charge * B. motion * C. positive charge * D. static 77. The cross-sectional area of a copper wire is 3 mm². It carries a current of 4.2 A. Find the drift velocity of the electrons in the wire. The electron density of the wire is 8.4 x 1028 e/m³. * A. 0.104 mm/s * B. 0.128 mm/s * C. 0.162 mm/s * D. 0.211 mm/s 78. Volt is the same as * A. joule/coulomb * B. coulomb/second * C. coulomb-second * D. joule/second 79. The resistance of a given wire is 0.02 Ω. Find the resistance of another wire of the same material, three times as long and one-half the cross-sectional area. * A. 0.06 Ω * B. 0.12 Ω * C. 0.03 Ω * D. 0.24 Ω 80. If the electric current and the cross-sectional area in a current carrying conductor is doubled, the new drift velocity of the electrons will * A. become 4 times as much * B. become half as much * C. become 2 times as much * D. remain the same **THE BOARD EXAM IS AN INDIVIDUAL COMPETITION!** **_&lt;3/5&gt;_** **STUDY HARDER, IT WILL BE YOU AGAINST ALL OTHERS** ## ROJAS ELECTRICAL ENGINEERING REVIEW CENTER **2nd Floor, Yap Building, 35 M. Velez St, Barangay Guadalupe, Cebu City** 81. Electrical energy is converted to heat at the rate of 7.56 kJ/min in a resistor which has 270 C/min passing through. Find the voltage difference across the resistor terminals. * A. 20 V * B. 24 V * C. 28 V * D. 32 V 82. Electric current in a wire is a flow of _&lt;ins>electrons&gt;_ electrons. * A. valence * B. charged * C. free * D. uncharged 83. Gold has a conductivity of 45 MS/m. Find the resistance of a 1 cm diameter gold connector that is 5 cm long. * A. 14.13 μΩ * B. 17.27 μΩ * C. 10.38 μΩ * D. 26.21 μΩ 84. The value of the temperature coefficient of resistance depends upon * A. length of the material * B. cross-sectional area of the material * C. volume of material * D. nature of the material _<ins>and temperature_ and temperature 85. A wire has a resistance of 10 Ω. It is stretched by one-tenth of its original length. Find its new resistance. * A. 10 Ω * B. 9 Ω * C. 12.1 Ω * D. 11 Ω 86. The curve representing Ohm's law is a _&lt;ins>curve&gt;_ curve. * A. parabolic * B. linear * C. sinusoidal * D. hyperbolic 87. Find the number of strands in a 1500 MCM cable, if each strand has a diameter of 0.094 inch. * A. 216 * B. 132 * C. 169 * D. 145 88. An atom that losses or gains electrons is called * A. an ion * B. a neutron * C. an isotope * D. a proton 89. Find the ohmic value of a carbon resistor color coded with green, black, gold and silver stripes. * A. 50 Ω ± 10% * B. 5 Ω ± 10% * C. 5 Ω ± 5% * D. 0.5 Ω ± 5% 90. A certain copper winding has a resistance of 0.25 Ω at a temperature of 18°C. Find the temperature rise in the winding when after a period of operation, the resistance increases to 0.31 Ω. * A. 58°C * B. 76°C * C. 61°C * D. 66°C 91. The condition in Ohm's law is that * A. ratio V/I should be constant * B. the temperature should vary * C. current should be proportional to voltage * D. the temperature should remain constant 92. Find the potential difference required to pass 3 A through a resistance of 28 Ω. * A. 9.33 V * B. 252 V * C. 84 V * D. 15.87 V 93. Energy may be measured in * A. joule-second * B. watt * C. kilowatt * D. watt-second 94. A copper wire of diameter 1 cm has a resistance of 0.15 Ω. It was drawn under pressure so that its diameter was reduced to 0.5 cm. Find the new resistance of the wire. * A. 2.0 Ω * B. 2.4 Ω * C. 3.2 Ω * D. 3.6 Ω 95. In a carbon composition resistor, in case the fourth stripe is not present, it can be concluded that the * A. resistance is highly accurate * B. resistor has less carbon * C. resistor is defective * D. tolerance limit is ±20% 96. A light bulb draws 300 mA when the voltage across it is 240 V. Find the resistance of the light bulb. * A. 72 Ω * B. 800 Ω * C. 1.25 Ω * D. 0.8 Ω 97. The resistance of a material is affected by four factors namely: length, cross-sectional area, type of material and * A. voltage * B. insulation * C. current * D. temperature 98. An atom has 10 protons, 15 neutrons and 10 electrons. Find its atomic mass number of the atom. * A. 20 * B. 10 * C. 35 * D. 25 99. The smallest part of matter that retains the characteristics of an element is called * A. ion * B. atom * C. isotope * D. electron 100. The insulation resistance if a single-core cable is 495 ΜΩ per km. If the core diameter is 2.5 cm and resistivity of insulation is 4.5 x 1014 ohm-cm, find the thickness of the insulation. * A. 1.15 cm * B. 1.35 cm * C. 1.25 cm * D. 1.45 cm 101. An instrument that is used to measure the diameter of a wire or cable to thousandths of an inch is a * A. Micrometer * B. Hydrometer * C. Galvanometer * D. Ruler 102. A carbon resistor is color coded with yellow, violet, orange and gold stripes from left to right. Find its ohmic resistance. * A. 470 Ω ± 5% * B. 0.47 Ω ± 5% * C. 47 ΚΩ ± 5%- * D. 470 ΚΩ ± 5% 103. Ohm's law does not applicable to * A. conductors * B. ac circuit * C. semi-conductors * D. dc circuits 104. If 10 m of a given wire, 0.13 cm in diameter has a resistance of 3.4 Ω, find the conductivity of the wire material. * A. 2.2 MS/m * B. 5.1 MS/m * C. 4.0 MS/m * D. 3.3 MS/m 105. Which of the following does not use heating effect of electric current? * A. Electric furnace * B. Immersion heater * C. Geyser * D. Vacuum cleaner 106. A length of a given wire has a resistance of 4.5 Ω. Find the resistance of another wire of the same material, three times as long and twice the cross-sectional area. * A. 6.75 Ω * B. 3 Ω * C. 27 Ω * D. 3.375 Ω 107. The atomic number of an element is determined by the number of * A. neutrons * B. neutrons plus protons * C. protons * D. electrons and protons 108. Find the ohmic resistance of a carbon resistor color coded with, red, black, yellow and gold. * A. 20 ΚΩ ± 5% * B. 200 ΚΩ ± 5% * C. 20 ΜΩ ± 5% * D. 2 ΜΩ ± 5% 109. The SI unit of electrical power is called * A. watt-hour * B. joule * C. coulomb * D. watt 110. Find the diameter of a wire having a cross-sectional area of 2500 circular mils. * A. 0.25 inch * B. 1.25 inches * C. 0.05 inch * D. 1.5 inches 111. The center portion of an atom is called * A. orbit * B. shell * C. valence * D. nucleus 112. A copper wire of 3 mm² cross sectional area carries a current of 5 A. Find the drift velocity of the electrons in the wire. * A. 0.122 mm/s * B. 0.134 mm/s * C. 0.128 mm/s * D. 0.142 mm/s 113. Conductors have _<ins>temperature coefficient of resistance&gt;_ temperature coefficient of resistance. * A. positive * B. negative * C. zero * D. infinite **THE BOARD EXAM IS AN INDIVIDUAL COMPETITION!** **_&lt;4/5&gt;_** **STUDY HARDER, IT WILL BE YOU AGAINST ALL OTHERS** ## ROJAS ELECTRICAL ENGINEERING REVIEW CENTER **2nd Floor, Yap Building, 35 M. Velez St, Barangay Guadalupe, Cebu City** 114. Electrical current is measured in terms of * A. electron pressure * B. watts * C. electrons passing a point * D. resistance 115. Find the number of electrons needed to form a charge of -2 nC. * A. 1.25 x 1010 electrons * B. 1.50 x 1010 electrons * C. 1.45 x 1010 electrons * D. 1.80 x 1010 electrons 116. The emf of a battery is equal to its terminal potential difference * A. under all conditions * B. only when the battery is being charged * C. only when a