Pass Benchmark: 70% (21/30) • Standard: USCG NMC / 46 CFR
USCG Marine Electrical Systems (Set 27)
30:00
|Question 1 of 30
Question Navigator
Correct Incorrect Pending Starred
Question 1 of 30
With what kind of starting equipment are most three-phase induction motors of five horsepower or less started?
Browse Questions in Set 27
30 MCQs #1 With what kind of starting equipment are most three-phase induction motors of five horsepower or less started? #2 Concerning the illustrated motor controller circuit, where is the location of the motor "run" indicator light? EL-0004 #3 Which of the following contactors or relays has a timing function for the transition from start to run? EL-0080 #4 As shown in the illustration, what type of motor and motor starter are featured? EL-0136 #5 As shown in the illustrated steering hydraulic pump motor controller, what statement is true? EL-0119 #6 As shown in figure "A" of the illustration, what is the purpose of the "test button"? EL-0178 #7 As shown in the illustrated feeder disconnect controller, what statement is true? EL-0138 #8 Which of the following pictures represents a magnetic reversing or two-speed motor starter? EL-0179 #9 Auto-transformer starters, sometimes called starting compensators, are sometimes used with larger polyphase induction motors. What function do they perform? #10 In general, what type of starter would be used to connect polyphase induction motors to full line voltage at the instant of start-up? #11 Assuming the ladder diagram of figure "1" and the corresponding input/output diagram of figure "2" represents a simple PLC motor controller, what statement is true? EL-0232 #12 Concerning figure "A" of the illustration, if the illustrated PLC ladder diagram is for a simple motor controller, what does "Input A" represent? EL-0236 #13 In the illustrated solid-state "soft" starter for a three phase induction motor as shown in figure "A", what is the name of the devices that are controlled by the gate control circuits? EL-0060 #14 By what means is the burning of controller contacts due to arcing, when opening, prevented? #15 As shown in the illustration of an electrically operated watertight door controller, what type of motor is used to open and close the watertight door? EL-0115 #16 As shown in the illustration of an electrically operated watertight door controller, how is reversal of the direction of motor rotation achieved? EL-0115 #17 As shown in the illustration of an electrically operated watertight door controller, how is the motor stopped automatically when the door is wedged closed? EL-0115 #18 As shown in the illustration of an electrically operated watertight door controller, how is the motor stopped automatically when the door is wedged open? EL-0115 #19 Which of the following statements about a three-phase wye connected alternator is correct? #20 Of the listed factors that influence the amount of RMS voltage induced in the windings of an AC generator operating at a constant 60 Hz frequency, which factor is variable during generator operation? #21 If the driving torque, such as that produced by a diesel engine, creates pulsations when coupled with a synchronous generator operating in parallel, the generator rotor may be periodically pulled ahead or behind its normal position as it rotates. How can this condition called hunting be reduced? #22 How are AC and DC generators are similar? #23 A DC generator which is used to supply direct current in order to provide magnetizing current to an AC generator field is commonly known as what? #24 From the information given in the illustration, what would be the maximum output amperage available from the emergency generator if it operated with a power factor of 0.9? EL-0106 #25 Which of the methods listed below is used to provide the rotational torque to cause an AC generator to turn? #26 How will the value of the output frequency change if the load is removed from a turbo generator having a governor speed droop setting of 3%? #27 From the information given in the illustration, which of the following statements is correct? EL-0106 #28 Two AC generators are operating in parallel and both are equipped with automatic voltage regulators. While standing watch, one generator is noted as having a greater lagging kvar value. In order to equalize the kvars between the generators manually, what should be done? #29 When paralleling two alternators the synchronizing lamps grow dim and are totally darkened as the synchroscope pointer approaches the 0° position. What does this indicate? #30 While paralleling two (2) AC generators using synchronizing lamps only, when will both lamps will go dark?
Question Discussion & Notes
0Have a doubt, memory trick, or exam update? Share your insights with fellow mariners.
Loading mariner discussions...