Assessment Test


1. The use of four diodes, in a full wave bridge rectifier circuit, will __________.


2. Raising the generator field excitation to a DC propulsion motor in a diesel- electric plant will__________.


3. If the solenoid coil burns out on a cargo winch with an electrical brake, which of the following conditions will occur?


4. The total opposition to current flow in an AC circuit which is a combination of resistance and reactance (X) and is measured in ohms is __________.


5. What type of transformer is used to protect technicians and operator from deadly electrical shock?


6. In testing a three phase delta winding for an open circuit using a megohmeter, you must __________ .


7. Conductors and busbars on a switchboard, panelboard or control board shall be located as to be free from __________.


8. A temperature instrumentation system for an engine room console consists of a resistance temperature detector (RTD ), a measuring bridge circuit and a meter or alarm circuit. Which statement is true concerning the measuring bridge circuit?


9. They are the used to protect motor branch circuit conductors from overload . I. Thermal relays II. Inverse time circuit breakers III. Time delay fuses


10. The connection of a stop switch in a motor is usually in a __________:


11. Amortisseur windings are installed in a synchronous motor to ___________.


12. One of the factors which determines frequency of an alternator is controlled by the __________.


13. Increasing the voltage output of an AC generator is obtained most practically by increasing the __________.


14. Routine AC motor maintenance should include periodic __________.


15. You are testing armature coils by applying low voltage. A short circuit will be indicated by a __________.


16. When sizing circuits or equipment always size the circuit component and transformers according to the apparent power, not the true power __________.


17. An open shunt field in a direct current machine may be located by connecting the field circuit to an external power source, equal to the rated field voltage or less, and tested with a voltmeter from __________.


18. Hysteresis is __________.


19. A device that connects the motor to the supply without the use of a resistance or autotransformer to reduce the voltage. It may consist of a manually operated switch or a master switch, which energizes an electromagnetically operated contactor__________.


20. Phase differences are expressed in __________.


21. Which of the following groups of electrical insulation materials is best suited for the highest operating temperature?


22. How many 20-ampere, 120-volt circuits are required for forty-two, 300 watt recessed fixture (non-continuous load) with a power factor of 85 percent?


23. Which of the listed conditions might contribute to the mica segments of a commutator to wear slower than the commutator bars?


24. To determine the state of charge of a nickel cadmium battery, which of the following would you use?


25. The motor controller contains three push button labeled “start”, “jog” and “stop”. When the Jog botton is pushed, the motor ___________.


26. Two AC generators of the same capacity are operating in parallel, one with a zero speed drop setting and the other with a 5% speed drop. If its capacity is not exceeded, the unit whose governor has the zero speed droop setting will _________ .


27. Crystals have very __________.


28. In an induction machine, the difference between its synchronous speed and its operating speed that may be expressed in the forms. A percent of synchronous speed, as a decimal fraction of synchronous speed or directly in RPM is called__________.


29. Self-inductance (CEMF) in a coil is not effected by the __________.


30. For an AC circuit, the power factor is given by the equation __________.


31. Cable bus shall not be permitted for __________.


32. A lead-acid battery that can deliver 20 amperes continuously for 10 hours has an ampere hour rating of __________.


33. Which of the following formulas listed is correct for determining the power?


34. Voltage generated by most AC generators is brought from the machine to the bus by means of __________.


35. Which of the following is the melted used to produce electron emission in most vacuum tubes ?


36. A water-soluble substance that is generally sour to the taste and is capable of reacting with a base solution to form a salt that contains hydrogen molecules or ions is __________.


37. Am amplifier intended to operate with low-level signals to provide gain an impedance matching to a level that can be handled by another amplifier is __________.


38. Parallel cells have the same voltages as one cell but have __________.


39. Which of the following statements is true if a 100 watt lamp and a 75 watt lamp are connected in parallel across a 100 volt power supply?


40. An enclosure constructed so that oil vapors, or free oil not under pressure, that may accumulate within the enclosure will not prevent successful operation of, or cause damage to, the enclosed equipment is __________.


41. A numbering system containing numbers and letters __________.


42. Coast Guard Regulation (46 CFR ) state that the minimum conductor size allowed for use in flexible electrical cords is __________.


43. Motor efficiency can be determined by which of the following formulas?


44. The opposition to the establishment of magnetic lines of force in a magnetic circuit is called the circuit’s __________.


45. Electrical leads and insulation on a motor should be painted with __________.


46. An electric generator in which the magnetic flux is provided by one more permanent magnets is __________.


47. A coil wound with 400 feet of No. 16 tinned copper wire is connected to a 12 volt battery. Determine the current if the resistance per 1000 feet of No. 16 tinned copper wire is 4.26 ohms.


48. An instrument designed to provide a graphic display of variation in a particular quantity being measured is __________.


49. When the transformer is used to step down the voltage, the low voltage winding is __________.


50. What electric device/s that is/are being used to protect both the motor and wiring from excessive resistance? I – circuit breaker II – overload relay III – safety use


51. It is an electrical device used to change the voltage by means of an electro-magnetic induction with AC current?


52. Most type of actuator use in the operation of the valve is called __________.


53. Decreasing the frequency in a capacitive circuit while maintaining a constant circuit voltage, will result in a/an __________.


54. What parts of an AC generator that can be installed as stationary at the same time can be installed as revolving? I – armature winding II – magnetic field III – slip ring


55. A liquid level sensor that is made of a float and is generally a hollow cylinder of ball working on direct action or displacement principles is called __________.


56. This will be observed or happen if a 100 watts electric bulb will be used in an AC circuit with frequency of 400 hertz compared to 60 hertz frequency?


57. The total resistance of a parallel circuit is always __________.


58. The magnetic material used to make permanent magnet is __________.


59. A desuperheater located in the steam drum of a boiler and is used for controlling superheat temperature is __________.


60. One of the methods used in temperature measurement is by means of gas filled thermometer. This type of instrument usually employs fluid under high pressure and the pressure is proportional to absolute temperature at constant volume. The usual temperature range is 50°C and the scale is linear. The most common type of fluid is __________.


61. What is the color of a DC commutator when wrong commutations is taking place?


62. A device capable of converting a pressure, temperature and level into an electrical equivalent is known as __________.


63. It is an arrangement between the engine order telegraph and the throttle hand wheel whereby if the telegraph is in the AHEAD position and the throttle hand wheel is in the ASTERN position it will display __________.


64. In 60 Hz AC system, the current will pass through one complete cycle in__________.


65. The function of providing thermal strip heaters in DC main propulsion motors is to _________.


66. To reverse the main shaft rotation on an AC diesel-electric propulsion vessel, you should __________


67. An advantage of a diesel electric propulsion plant is __________.


68. It is where rapid maneuvering response with a high degree of main propeller shaft control in ships is __________.


69. The twisting force developed by a motor and applied to a shaft is __________.


70. The electric current is the flow of electrons through a conductor, the unit of rate of this flow is known as __________.


71. A transformer that accepts low input voltage then delivers a high output voltage is called __________.


72. What is the true statement about a wound-rotor induction motor?


73. What consideration should be given when choosing a battery for a particular application?


74. The safe method of cleaning dust and foreign particles from electrical equipment is _________.


75. What particular circuits does a delayed-action fuse is used?


76. What should be check if the circuit breaker is tripped?


77. Air gap of induction motors shall be checked with a feeler gauge in order to prevent __________.


78. How will you adjust the frequency of an AC generator?


79. What is the trouble of humming or buzzing in electric contact?


80. What causes why the contact of a magnetic controller is welded?


81. Which of the following is not a source of grounds in an electrical machinery due to insulation failure?


82. A device used to protect short circuits in a molded-case circuit breaker is __________.


83. Reverse current relay prevents DC generator motorization by _________.


84. Larger size of wires are made in the form of a cable consisting of several small strands to __________.


85. If an electric drill draws 20 amperes at 220 voltage, what is its resistance?


86. What is the percentage of overload most generators can withstand?


87. DC generator commutation can be corrected for armature reaction by the use of __________.


88. What is the equivalent 1 horsepower of an electric motor that develops a power of 858 watts?


89. On a vessel with turbo-electric drive, which of the following conditions would indicate that the propulsion motor had dropped out of synchronization with the propulsion generator?


90. To anneal a copper gasket, you should heat the gasket __________.


91. Which of the following statements represents an application of silicon controlled rectifier?


92. While testing a transistor with an ohmmeter, both the forward and reverse readings are almost in the infinity range. This would indicate that the transistor is __________.


93. To minimize magnetic field interaction between electrical conductors in physical proximity, it is best to keep them __________.


94. Which of the following statements is correct in order to ensure safety prior to entering a pumproom?


95. A high-input-impedance amplifier circuit that has unity voltage gain with its input and output signals in phase is known as __________.


96. A ground on a particular phase of a three phase low voltage distribution system would be indicated by __________.


97. When soldering a printed circuit board component, you should be careful to prevent circuit and board damage by __________ .


98. When trouble shooting motor controllers, a shorted relay or contactor coil is often indicated by __________.


99. A temperature measuring assembly that consists of a sensing bulb, capillary tube and pressure element is __________.


100. What power would be consumed in each of the branch resistors of the circuit if the source is 30 volts, the resistance for R1 is 10 ohms, R2 is 10 ohms and R3 is 10 ohms are connected in series?


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