Assessment Test


1. Which of the following is not a valid expression of Ohm?


2. What is the lagging effect between the magnetizing force 3 applied and the flux density?


3. The concept whereby a small voltage is generated by a conductor with current in an external magnetic field refers to:


4. What is the property of the magnetic circuit that resists the establishment of flux?


5. Which of the following alloy does a manganin made of?


6. When you demagnetize properly by applying an AC field then gradually reduced it to zero, it is called:


7. What is the law that determines polarity of an induced voltage?


8. What is the quantity of magnetizing force needed to counter balance the residual magnetism of a magnetic material?


9. One of the following characteristics of a resistive material which do nor change its resistive material which do not change its resistive value with respect to time is its.


10. Refers to the most important components in controlling flow of electrons.


11. What is residual magnetism?


12. The force between two magnetic poles in relation to their pole strength is:


13. What is a symbol that represents a quantity or a single object?


14. What do you call the non-metallic material that has ferromagnetic properties?


15. What is the basic unit for measuring current flow?


16. Refers to a force of field that exists between ions where they either repel or attract each other.


17. It is called the flux density produced within, due to its own induced magnetism.


18. It is composed of a series of energy levels containing the valence electrons:


19. How many diode will you use in designing a half-wave rectifier power supply?


20. What is the magnetic equivalent to electrical voltage?


21. It is defined as anything that occupies space and has weight.


22. Materials that can be easily magnetized in both direction.


23. How can electrical current be induced with a coil and a magnet?


24. What is the property of a material which opposes creation of magnetic flux?


25. The intensity of a magnetic field directly related to the magnetic force exerted by the field.


26. The freezing point of the electrolyte in a fully charged lead-acid battery will be ________.


27. A flickering ground detection lamp on a DC system would indicate a_________.


28. A molded-case breaker provides protection against short circuits by using a(an) ________.


29. The function of a stepdown, potential transformer is to reduce the load_______.


30. A circuit in which a fuse has blown be considered as a/an_____.


31. Circuits are protected against overheating by means of a/an _____.


32. Using a fuse whose rating is higher than necessary _____.


33. A circuit that has one of two wires in contact with the hull of a ship, is called a _.


34. Where a thermal-acting breaker is required to be used in an area of unsually high, low, or constantly fluctuating temperatures , an ambient compensating element must be used. This element consists of a___.


35. Fuse elements are made of zinc or any alloy of tin and lead, therefore, the melting point of the fuse element must be___.


36. Which of the listed ranges represents the proper corrected specific gravity for the electrolyte of a fully charged portable lead-acid battery?


37. The basic operating principle of a transformer is attributed to ______.


38. Fuses placed in series with a thermal tri-type circuit breaker are used for ______.


39. The basic type of D.C. motor speed control where a generator armature directly feeds the motor armature and the motor and generator fields are excited by a separate D.C. source is called____.


40. Which of the following devices should be used to measure the temperature of a battery electrolyst.


41. The speed of a wound-rotor induction motor _____.


42. Which of the AWG wire sizes listed below would have the smallest diameter?


43. In a three-wire, 230/115 volt DC system, the potential between neutral and negative is ____.


44. Transformers aboard ship are used with AC generators to ____________.


45. Speaking of D.C. motor brushes can be caused ___.


46. A device which is normally used to prevent an action from occurring until all other required conditions are met is called a/an _____.


47. In a three wire, 230/115 volt, DC distribution system the voltage between the two hot legs is____.


48. If a fuse of correct size and type blows frequently, ___________.


49. When troubleshooting motor controllers, a shorted relay or contactor coil is often indicated by__.


50. The armature cores of D.C. motors are constructed with laminations to ________.


51. The rotor of a synchronous motor operates in synchronism with the rotating field because:


52. When the starting DC shunt on compound motor, the field rheostat should be set for_.


53. Transformer cores are laminated to reduce____.


54. What is the approximate voltage produced by a nickel-cadmium battery cell?


55. The charging of lead-acid storage batteries will always result in_______.


56. An across the line starter provides ____________.


57. You can determine if a circuit breaker is tripped by_________.


58. The purpose a main switchboard circuit breaker reverse power trip is to______.


59. As a general rule, the first troubleshooting action to be taken in checking faulty electric control devices is to________.


60. Which of the listed forms of water should be added to a lead-acid battery?


61. A saturable reactor uses relatively small DC currents to control_______.


62. A shore power circuit breaker should be closed only______.


63. Which of the following statements is true concerning a step down transformer in an operating AC power circuit?


64. If a DC motor runs faster than designed, with all other conditions being normal, the possible cause could be a/an_____.


65. A reverse-current relay will prevent DC generator motorization by ________.


66. Electric cables are formed of stranded wire to ____.


67. A twelve volt lead acid battery is constructed of________.


68. A saturable-core rector operates on the principle of controlling winding


69. When changing fuses and the spring clips are found to have lost their grip, they should be replaced or______.


70. A closed circuit fault in an electrical conductor is a fault described as a/an____.


71. The resistance of electric wire will decrease as its________.


72. The synchronous speed of an induction motor is the _________.


73. On vessels equipped with a general alarm system, the source of power for the system must be taken from the ________.


74. When troubleshooting a motor controller, all indications are that a relay coil should be energized. If there were no magnetic pull with rated voltage measured across the coil, the most probable cause would be that the_____.


75. In addition to short circuits and sustained overloads, fuses are likely to blow due to _______.


76. What direction is the magnetic field about a conductor when current is flowing?


77. What is the relative permeability of a paragmatic substance?


78. Which of the following material possesses permeabilities slightly less than that or free space?


79. The term describes a material whose resistance remains relatively constant with changes in temperature?


80. In applying the right hand rule by holding a conductor with your right hand so that the thumb represents the current, the encircling fingers around the conductor represent.


81. Steel is hard to magnetize because of its:


82. What is the maximum equivalent of electric current?


83. What is the physical motion resulting from forces of magnetic fields?


84. They are the imaginary line used to describe the patterns of the magnetic filed about a magnet.


85. The motion of charged particles especially colloidal particles through a relative stationary liquid under the influence of an applied electric fields provided is called.


86. Process by which a magnetic substance becomes a magnet when it is placed near a magnet.


87. It is the property of the material used which enable it to attract pieces of iron ___.


88. What does SI magnetic flux refer?


89. What do you call the ratio between the intensity of magnetization produced in a substance to the source of magnetizing force?


90. Component of a transformer that provides the path for magnetic lines of flux ___.


91. Which of the following determines the strength of a magnetic field around a conductor?


92. The transfer of energy from one circuit to another circuit by electromagnetic induction is called:


93. The ability of a material to conduct magnetic flux through it refers to:


94. What is the term called magnetic field?


95. What is the unit of magnetic flux density?


96. The science of physical phenomena at very low temperature, approaching absolute zero is called:


97. What is the law whereby the attraction or repulsion between two magnetic poles is directly proportional to their strength?


98. Where do you classify cobalt as material?


99. What is called the magnetic field?


100. An alloy that changes directly from solid to liquid with no plastic or semi-liquid state is known as ___________


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