If the energy input is significantly reduced to the prime mover of one shipboard alternator operating in parallel with others, that alternator will _____________. A. continue to operate at no load B. lose its load and overspeed C. begin to motorize and then trip out D. slow down and operate at reduced load

1 Answer

Answer :

Answer: C

Related questions

Description : If field excitation is suddenly lost to an alternator operating in parallel, that alternator will _____________. A. supply excessive current to the bus B. operate at the same load, but with reduced voltage C. lose its load and tend to overspeed D. become overloaded and slow down

Last Answer : Answer: C

Description : A loss of field excitation to an AC generator while operating in parallel will cause it to ____________. A. absorb more and more load due to decreased armature reaction B. lose its load due to ... polarity D. lose its load, begin to motorize, trip out on reverse power relay, and possibly overspeed

Last Answer : Answer: D

Description : If a unloaded shunt motor's field were weakened by rheostat resistance or by an open circuit, the motor would _________. A. overspeed due to reduced CEMF B. stop because of low flux C. continue to run at base speed D. slow down and overheat

Last Answer : Answer: A

Description : The division of the kilowatt load between two AC generators operating in parallel is controlled by the settings and characteristics of the _____________. A. voltage regulators B. field rheostats C. reverse power relays D. prime mover governors

Last Answer : Answer: D

Description : Kilowatt load is divided between two AC generators operating in parallel by _____________. A. adjusting the governor controls B. varying the excitation voltage C. increasing both prime mover speeds simultaneously D. decreasing both prime mover speeds simultaneously

Last Answer : Answer: A

Description : The output voltage of a 440 volt, 60 hertz, AC generator is controlled by the _____________. A. prime mover speed B. exciter output voltage C. load on the alternator D. number of poles

Last Answer : Answer: B

Description : Low voltage releases as used in some shipboard motor starter and control equipment will have which of the following characteristics? A. They trip circuit contactors when the motor starts to overspeed. B. ... coil of the starter. D. They allow the motor to restart upon restoration of normal voltage.

Last Answer : Answer: D

Description : In the illustration, the signal from the device connected to terminals 18 and 19 is __________. EL-0046 A. prime mover speed feedback B. loss of control alarm when comparing with the input signal ... slip between the prime mover and the alternator D. to shut down the prime mover if overspeeding

Last Answer : Answer: A

Description : Which of the following conditions will occur if the solenoid coil burns out on a cargo winch with an electrical brake? A. The brake will be set by spring force. B. The motor will overspeed and burn ... the cargo boom will fall. D. Nothing will happen; the winch will continue to operate as usual.

Last Answer : Answer: A

Description : An operating characteristic appearing on the name plates of shipboard AC motors is _____________. A. the type of winding B. input kilowatts C. temperature rise D. locked rotor torque

Last Answer : Answer: C

Description : The standard method of controlling the output voltage of a 440 volt, 60 Hz, AC generator is accomplished by adjusting the ____________. A. prime mover speed droop B. number of poles C. alternator field excitation D. load on the alternator

Last Answer : Answer: C

Description : The output voltage of a 440 volt, 60 Hz AC generator is controlled by the ______________. A. load on the alternator B. load on the prime mover C. speed of the prime mover D. exciter output voltage

Last Answer : Answer: D

Description : If the pointer of the synchroscope is rotating in the slow direction when you are preparing to parallel two alternators, the _____________. A. incoming machine is turning faster than the load alternator B ... alternator is ready to split D. incoming machine is beginning to pick up some of the load

Last Answer : Answer: B

Description : If the excitation of an alternator operating in parallel is decreased below normal, its _____________. A. power factor will change in the lagging direction B. power factor will change in the leading direction C. ampere load will be greatly increased D. kilowatt load will be greatly decreased

Last Answer : Answer: B

Description : A change in field excitation of an alternator operating in parallel will cause a change in its _____________. A. alternator frequency B. kilowatt load C. voltage output D. all of the above

Last Answer : Answer: C

Description : As load is added to a shunt motor, the motor will _________. A. speed up B. continue to operate at the same speed C. slow down slightly D. stop

Last Answer : Answer: C

Description : If air gap readings for an electical generating machine have changed significantly from the last reading, you should check _________. A. the bearings B. insulation readings and machine cleanliness C. the prime mover thrust bearing D. the field coil bolts for the proper torque values

Last Answer : Answer: A

Description : A generator is prevented from becoming motorized by the use of a/an _____________. A. overspeed trip B. reverse power relay C. back pressure trip D. governor controls

Last Answer : Answer: B

Description : Automatic voltage regulators provided on switchboards function to _____________. A. regulate the AC load on the generator B. protect the switchboard from high voltage C. govern prime mover speed to control voltage D. vary the field excitation to the generators

Last Answer : Answer: D

Description : The power factor at which a paralleled AC generator operates is usually adjusted by the _____________. A. connected load B. prime mover speed C. field excitation D. generator's rated voltage

Last Answer : Answer: C

Description : If many turns of an alternating current coil for a contactor become short circuited, the coil _____________. A. will continue to operate B. will probably burn out immediately C. will operate on reduced current D. temperature will drop

Last Answer : Answer: B

Description : If many turns of an alternating current coil for a contactor become short circuited, the coil _____________. A. temperature will drop B. will probably burn out immediately C. will continue to operate D. will operate on reduced current

Last Answer : Answer: B

Description : The power factor of an AC generator operating singularly is determined by the __________. A. connected load B. prime mover speed C. field excitation D. generator's rated voltage

Last Answer : Answer: A

Description : The frequency of an AC generator is adjusted by means of the ____________. A. main alternator field rheostat B. exciter field rheostat C. prime mover governor control D. equalizing reactor

Last Answer : Answer: C

Description : What happens if speed of prime mover is changed keeping excitation of alternator constant?

Last Answer : If speed of prime mover is changed, the speed of alternator also changes hence frequency also changes. The frequency increase with increase in steam input and hence speed and vise versa.

Description : What happens if excitation of alternator is changed keeping speed of prime mover constant?

Last Answer : The emf induced will be changed and hence terminal voltage will also change. The terminal voltage will increase with increase in excitation and vise versa.

Description : When shipboard electrical distribution circuits are connected in parallel, additional parallel circuits will cause the total circuit resistance to _____________. A. increase, causing a drop in the line current B ... an increase in the line voltage D. decrease, causing an increase in the line current

Last Answer : Answer: D

Description : If the centrifugal switch or relay used for cutting out the starting winding of a split-phase induction motor fails to open once the motor is in operation, the _____________. A. motor will overspeed B ... C. motor will immediately stall under load D. motor torque will be above normal at rated speed

Last Answer : Answer: B

Description : In the illustrated electronic governor, the circuit card connected to the potential and current transformers is for ________. EL-0046 A. increasing the signal strength to the governor to ... from motorization D. conditioning the load through the use of a magnetic amplifier current transformer

Last Answer : Answer: A

Description : As load is added to an AC generator provided with constant field excitation, the prime mover slows down with the effect of ____________. A. lowering frequency and lowering generated ... C. increasing frequency and lowering generated voltage D. lowering frequency and increasing generated voltage

Last Answer : Answer: A

Description : If three AC generators are operating in parallel, and one of them were to 'pull out' of synchronism with the other two generators, the ____________. A. normally operating AC generators will ... AC generators will overspeed and unload D. AC generator pulling out of synchronism will become motorized

Last Answer : Answer: B

Description : Severe vibration, accompanied by flashover at the collector rings of an alternator operating in parallel, is a symptom of _____________. A. reverse current motorization B. loss of synchronism C. destructive overspeeding D. reversed polarity

Last Answer : Answer: B

Description : If a three-phase induction motor is operated under a light load and it develops an open in one of its supply lines, the motor will _____________. A. continue to run, but will vibrate and have reduced ... speed up due to the reduced number of poles C. run cooler due to reduced current flow D. stop

Last Answer : Answer: A

Description : A three-phase alternator is operating at 450 volts, 250 amps at 0.6 power factor. If the power factor increases to 0.8, the kw load potential will increase by _____________. A. 38.525 kw B. 116.91 kw C. 155.88 kw D. 194.85 kw

Last Answer : Answer: A

Description : The voltage output of an AC generator is accurately controlled by _____________. A. changing the sensitivity of the prime mover to large changes in voltage B. varying the reluctance of the air gap C. varying the DC exciter voltage D. shorting out part of the armature windings

Last Answer : Answer: C

Description : A constant output voltage from an AC generator is maintained by the _____________. A. prime mover governor B. exciter generator C. voltage regulator D. reverse power relay

Last Answer : Answer: C

Description : In an AC synchronous motor electric propulsion plant, propeller speed is controlled by varying the _____________. A. prime mover speed B. electric coupling field strength C. number of energized main motor poles D. propulsion generator field strength

Last Answer : Answer: A

Description : An alternator operating in parallel begins to vibrate severely and eventually trips out on the reverse power relay. The cause of the vibration was a result of ______________________. A. the ... C. the alternator was operating out of synchronism D. flashover at the alternator collector rings

Last Answer : Answer: C

Description : To remove an alternator operating in parallel with another unit from the main electrical bus, you must FIRST _________. A. adjust the power factor on both units B. set the desired voltage on ... C. open the circuit breaker on the outgoing alternator D. remove the load from the outgoing alternator

Last Answer : Answer: D

Description : On electrical generators one of the bearings is isolated from the bedplate. This insulating block should not be painted and must be kept clean to ___________. A. protect operating personnel from shock ... the prime mover as it warms up D. eliminate shaft currents to prevent damaging the bearings

Last Answer : Answer: D

Description : To increase the frequency of an operating AC generator, you should ____________. A. increase the field excitation B. decrease the field excitation C. increase the number of magnetic poles D. increase the speed of the prime mover

Last Answer : Answer: D

Description : What type of prime mover requires a specially designed high-speed alternator?

Last Answer : Steam turbine.

Description :  The driving power from the prime-mover driving the alternator is lost but the alternator remains connected to the supply network; the field supply also remains on. The alternator will: A) ... as a synchronous motor but will rotate in a reverse direction to that corresponding to generator action 

Last Answer : The driving power from the prime-mover driving the alternator is lost but the alternator remains connected to the supply network; the field supply also remains on. The alternator will: behave as a synchronous motor and will rotate in the same direction

Description : In the illustration, the contacts between terminals 26 and 27 should be closed when _________. EL-0046 A. using one generator in isochronous mode only B. using two or more generators in ... through varying loads in parallel or single operation D. the circuit breaker is closed for that generator

Last Answer : Answer: C

Description : You are attempting to parallel two AC generators and the synchroscope pointer stops at a position other than 0°. If you close the circuit breaker at this moment _____________. A. the incoming ... hazardous condition will be created by the incoming machine being at a higher frequency than the bus

Last Answer : Answer: C

Description : The purpose of a main switchboard circuit breaker's reverse-power trip is to _____________. A. prevent main circuit overload B. protect the circuit breaker blowout coil C. prevent alternator motorization D. prevent low voltage tripout

Last Answer : Answer: C

Description : A three-phase, induction-type motor experiences an open in one phase. Which of the listed automatic protective devices will prevent the machine from being damaged? A. Overspeed trip B. Thermal overload relay C. Three-pole safety switch D. Magnetic blowout coil

Last Answer : Answer: B

Description : The division of the reactive KVA load between paralleled AC generators is initiated by the ______________. A. prime mover governors B. voltage regulators C. phase balance relay D. proportioner

Last Answer : Answer: B