西安交通大学19秋《专业英语》在线作业（随机）答案

网院作业

【奥鹏】[西安交通大学]西交《专业英语》在线作业
试卷总分100得分100

第1题Resistorsare()elements.
A、passive
B、active
C、independentsources
D、dependentsources
正确答案
第2题Anelectricheaterdraws10Afroma120Vline.Theresistanceoftheheateris().
A、1200?
B、120?
C、12?
D、1.2?
正确答案
第3题Thealgebraicsumofallvoltagesaroundaloopis().
A、zero
B、indefinitevalue
C、sumofvoltagerises
D、sumofvoltagedrops
正确答案
第4题ONOFFinformationcanberepresentedby()signal.
A、adigital
B、ananalog
C、adiscrete
D、acontrol   
正确答案
第5题Theprocessquantizingthecontinuousvaluesintoabinaryscaleiscalled().
A、digitaltoanalogconversion
B、digitaltodigitalconversion
C、analogtodigitalconversion
D、analogtoanalogconversion
正确答案
第6题Thewideapplicationofoperationalamplifiersliesinadvantageofusing().
A、positivefeedbacknetworks
B、largeopencircuitgain
C、negativefeedbacknetworks
D、smalloutputimpedance
正确答案
第7题Whenaninductionmotorwith10polesissuppliedby50Hzthreephaseacpowersourcethesynchronousrevolutionsperminuteis().(Synchronousr/min=120f/p)
A、1000
B、900
C、700
D、600
正确答案
第8题Theelectricmachinethatoperatesatspeedsabovesynchronousspeedworksin()region.
A、motoring
B、generating
C、plugging
D、stopping
正确答案
第9题Atransformerisadevicethatcanconvertoneacvoltagetoanotheracvoltagethroughtheactionof().
A、anelectriccircuit
B、amagneticfield
C、anelectricfield
D、acouplingcircuit
正确答案
第10题Theprimarywindingisconnectedto().
A、thepowersource
B、theload
C、themeasurementinstrument
D、themotor
正确答案
第11题Copperlossesare()lossesintheprimaryandsecondarywindingsofthetransformercore.
A、inductive
B、capacitive
C、resistive
D、reactive
正确答案
第12题()canprovideanasynchronouslinkbetweentwoacelectricpowersystemwithdifferentnominalfrequencies.
A、TheHVDC(highvoltageDC)transmission
B、TheEHV(extrahighvoltage)ACtransmission
C、TheACdistribution
D、Generators
正确答案
第13题Thegeneratorvoltagesareusuallysteppeduptothetransmissionvoltagelevelby().
A、seriescapacitor
B、parallelreactors
C、stepuptransformers
D、stepdowntransformers
正确答案
第14题Theobjectiveoftheoptimaleconomicoperationofpowersystemsis().
A、tominimizethetotalproductioncost
B、tomaintainfrequencyconstant
C、tomaintainvoltagesconstant
D、toensurebalancebetweengenerationandload
正确答案
第15题Anyprotectionschemeconsistsbasicallyof().
A、twoelements
B、threeelements
C、fourelements
D、fiveelements
正确答案
第16题Theprotectiveschemethatsenseszerosequencecurrentandoperatesasnecessaryiscalledas().
A、overcurrentprotection
B、zerosequenceprotection
C、negativesequenceprotection
D、directionalprotection
正确答案
第17题Thedistanceprotectionisappliedtoprotect().
A、transformers
B、generators
C、transmissionlines
D、buses
正确答案
第18题Thethermalenergyofthesteamisconvertedinto()energybytheturbine.
A、electrical
B、mechanical
C、chemical
D、potential
正确答案
第19题()isusedascoolantinlightwaterreactors.
A、Gas
B、Organiccompound
C、Moltensalt
D、Water
正确答案
第20题Intheformof()theoutputiscontinuouslyfedbackandcomparedwiththereferenceinput.
A、continuouscontrol
B、discontinuouscontrol
C、discretedatacontrol
D、sampleddatacontrol
正确答案
第21题Theoveralltransferfunctionistheratioofthetransformofthecontrolledvariabletothetransformof().
A、thecontrolledvariable
B、thereferenceinput
C、thefeedback
D、theoutputvariable
正确答案
第22题Thesystem’scharacteristicequationcanbeusedtodetermine()ofalineartimeinvariantsystem.
A、thestability
B、magnitudeofthesteadystateerror
C、thecontrollability
D、theobservability
正确答案
第23题Intherootlocusmethodtheactualtimeresponseofasystemcanbeobtainedbymeansof().
A、theinverseFouriertransform
B、theinverseLaplacetransform
C、theFouriertransform
D、theLaplacetransform
正确答案
第24题TheBuck(降压式变换器)isa()converter.
A、voltagestepup
B、currentstepdown
C、currentstepup
D、resistance
正确答案
第25题Mostdesktopcomputersuseaseparate()asadisplaydevicewherenotebookcomputersuseaflatpanelLCDscreen(liquidcrystaldisplayscreen)thatattachedtothesystemunit.
A、keyboard
B、Mouse
C、Monitor
D、harddisk
正确答案
第26题Adesktopcomputer’ssoundcardsendssignalstoexternal().
A、printer
B、speaker
C、Modem
D、keyboard
正确答案
第27题DatastoredinRAM()whenthepowerofthecomputeristurnedoff.
A、isheldpermanently
B、permanentlydisappears
C、isheldtemporarily
D、temporarilydisappears
正确答案
第28题Thenotebookcomputersuse()asstandarddisplayequipment.
A、CRTdisplay
B、LCDs
C、LED
D、TVscreen
正确答案
第29题Imageclarityonacomputerscreenismeasuredwith().
A、screensize
B、dotpitch
C、resolution
D、colordepth
正确答案
第30题()thatconnectsatleasttwonetworksmakesdecisionaboutthebestroutefordata.
A、Amodem
B、Anetworkcard
C、Ahub
D、Arouter（路由器）
正确答案
第31题##thedirectcurrentisusefulithasonegreat##thatisthereisnoeasyeconomicalwaytoincreaseordecreaseits##.Thealternatingcurrenthasnotthisdisadvantage.##aspecialdeviceitis##totransformahighvoltageintoa##voltageoralowvoltageintoahighvoltage.The##thatweusetotransformthevoltageiscalleda##.Thealternatingcurrentcan##bechangedeasilyintothedirectcurrent.Thedevicewhichcandothisisspokenofasa##.
正确答案
第32题Thereare##indsofcurrentdirectcurrent(DC)andalternating##(AC).Adirectcurrentisacurrentflowingina##alwaysinonedirection.##alternatingcurrentisacurrent##changingitsdirectionofflow.Theelectriccurrent##throughelectric##linesis##current.ThisisbecauseACiseasyto##andmoreeconomicalwhenwetransmititoverlong##.
正确答案