Pass Benchmark: 70% (21/30) • Standard: USCG NMC / 46 CFR
USCG Marine Electrical Systems (Set 46)
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Question 1 of 30
In mounting a transducer for a depth sounding system, what would represent an ideal location?
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30 MCQs #1 In mounting a transducer for a depth sounding system, what would represent an ideal location? #2 In viewing the liquid crystal display for the illustrated depth sounder data display unit, what should be done if the graphic display of the ocean bottom is no longer visible on the screen? Illustration EL-0186
Illustration EL-0186: the U.S. Coast Guard has not released this illustration. #3 As shown in the illustrated block diagram for a digitized echo sounding system, what statement is true concerning the transmission and reception of acoustical energy? EL-0185
Illustration EL-0185: the U.S. Coast Guard has not released this illustration. #4 As shown in the illustrated block diagram for a digitized echo sounding system, what statement is true concerning the function of the transducer? EL-0185
Illustration EL-0185: the U.S. Coast Guard has not released this illustration. #5 As shown in the illustrated graph showing the effect of overshoot on steering system control stability, what statement is true? EL-0188
Illustration EL-0188: the U.S. Coast Guard has not released this illustration. #6 As shown in the illustrated adaptive digital steering control system functional block diagram and listed system interface signals table, what would the rudder order signal output voltage to the rudder servo amplifier be for a rudder order of 15 degrees right rudder? Assume that left rudder order signals are negative in polarity and that right rudder order signals are positive in polarity. EL-0191
Illustration EL-0191: the U.S. Coast Guard has not released this illustration. #7 As shown in the illustrated adaptive digital steering control system functional block diagram and listed system interface signals table, what would the rudder order signal output voltage to the rudder servo amplifier be for a rudder order of 20 degrees left rudder? Assume that left rudder order signals are negative in polarity and that right rudder order signals are positive in polarity. EL-0191
Illustration EL-0191: the U.S. Coast Guard has not released this illustration. #8 As shown in the illustrated digital gyrocompass functional block diagram and the associated communication protocols table, what would the rate of turn signal voltage be if the rate of turn is 30 degrees per minute to port? Assume that the rate of turn to port signal voltage is negative in polarity and that the rate of turn to starboard signal voltage is positive in polarity. EL-0194
Illustration EL-0194: the U.S. Coast Guard has not released this illustration. #9 Assuming the alternator shown in figure "A" of the illustration is equipped with a diode plate as configured in figure "D", what is the purpose of the diode plate? Illustration EL-0037 #10 Two AC generators of the same capacity are operating in parallel. One with a zero speed droop setting and the other with a 5% speed droop. If its capacity is not exceeded, what will be the characteristic of the unit whose governor has the zero speed droop setting? #11 What are the operational characteristics of the two alternators with the speed-droop curves shown in figure "A" of the illustration? EL-0025 #12 In preparation for paralleling generators, if the electric plant condition is as shown by graph "A", what would be the rotational status of the synchronizing lamps as shown in circuit "B"? Illustration EL-0002 #13 From the illustration shown in figure "C", what can be determined from the speed droop characteristics of generator A and generator B? EL-0025 #14 As shown in figure "B" of the illustration, what is the purpose of the synchronous compensator? EL-0133 #15 As Chief Engineer, to prevent the motorization of an alternator what safety device would you have checked quarterly? #16 As shown in the illustrated alternator protection scheme diagram, what device provides the input to the over current inverse time relay "OCIT", the over current instantaneous trip "OC (inst.)", and the negative phase sequence relay "NPS"? EL-0067 #17 As shown in the illustrated diagnostic setup for locating a shorted field coil of a ten- pole salient pole alternator, if 240 VAC 60-Hz is applied across the brushes, what would be the voltage drop across field coil #4 if that field coil had shorted turns and the other field coils were free of shorts? EL-0202 #18 What may be the cause of an AC generator to fail to produce a voltage? #19 As shown in the illustrated alternator protection scheme diagram, under what
circumstances would an earth leakage relay (EL) be used? EL-0067 #20 As shown in the illustration, if the port propulsion motor field excitation circuit experienced a failure, what individual component failure would allow the use of the standby excitation transformer and standby field controller to resume normal operation? Illustration EL-0164 #21 While standing an "at sea watch" onboard a modern rectified DC diesel-electric drive ship you notice the transformer core temperature slowly rising. What should be your FIRST action? #22 While underway onboard a DC diesel electric drive ship, you notice excessive sparking of the brushes on the main propulsion motor. What should be your FIRST action? #23 Upon failure of the normal power supply, how is the emergency generator placed on the line to feed power to the emergency bus? #24 In the illustrated one line diagram, if the ship's service generator on line fails, what statement is true concerning the operation of the emergency diesel generator? EL-0014 #25 As shown in the illustrated one-line diagram of a two-tiered emergency power system for a passenger ship, what statement is true? EL-0166 #26 From the information given in the illustration, which of the following statements is correct? Illustration EL-0106 #27 Before any work on electrical or electronic equipment is performed, which of the following precautions should be carried out? #28 For the purposes of safety and determining the shock hazard, nominal voltage is defined as the normal electrical system design voltage. This can be determined from what is displayed on nameplates, data plates, schematics, or single-line diagrams. What does the nominal voltage represent? #29 What is the minimum threshold voltage at which the skin offers no appreciable resistance to electrical current flow and is known as the "skin-puncture voltage"? #30 Which activity or event accounts for the most electrical accidents resulting in injury?
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