雨课堂学堂在线学堂云《电气工程英语( 安徽理大)》单元测试考核答案

注：不含主观题第1题判断题(1分)Electricityisonekindofinventionsbyhumanbeing,andwidelyusedforprovidingpowerforbuildings,electricdevices,andevensomeautomobiles.第2题判断题(1分)Powerengineering,alsocalledpowersystemsengineering,isasub-fieldofelectricalengineeringthatdealswithelectricityanddesignofrelatedelectricaldevicessuchastransformers,generators,motorsandpowerelectronics.

第3题判断题(1分)Theadventoftransistorin1956wasthegreatinventionandthefore-runningofthemicroelectronicrevolution.

第4题判断题(1分)Electricalengineersareincreasinglyrelyingoncomputer-aideddesign(CAD)systemstocreateschematicsandlayoutcircuits.第5题判断题(1分)moreandmoreelectricalandelectricsengineerswillbegreatlyneededinthefuturebecauseoftherapidinnovationanddevelopmentofnewtechnologies.第6题填空题(1分)Electricalengineeringisoneofthenewerbranchesofengineeringanddatesbacktothelate19thcentury,whichdealswithtechnologyof____.正确答案：:["electricity"]第7题填空题(1分)

Electricity

isasetofphysicalphenomenaassociatedwiththepresenceof

____.正确答案：:["electriccharge"]第8题填空题(1分)LawofInductionproposedbyEnglishphysicistMichaelFaradayin1831satesthe____inacircuitisproportionaltotherateofchangeinthemagneticfieldthroughthecircuit.正确答案：:["voltage"]第9题填空题(4分)

Electricalengineeringhasmanysub-disciplinesandthemostcommonofthemare____,____,electronicsengineering,____,____,instrumentationsengineering,mechatronicsengineeringandaerospaceengineeringandrobotics.

正确答案：:["powerengineering"]正确答案：:["controlengineering"]正确答案：:["signalprocessingengineering"]正确答案：:["telecommunicationsengineering"]第10题填空题(1分)

Controlengineering,orcontrolsystemsengineering,isanengineeringdisciplinethatapplies____todesignsystemsorcontrollersthatcausesystemstobehaveinacertainway,usingmicro-controllers,programmablelogiccontrollers,digitalprocessorsandelectricalcircuits.

正确答案：:["automaticcontroltheory"]第11题填空题(1分)

The

____wasthefoundationofallelectronics,including

radios,televisionandradar,untilthemid-20thcentury.

正确答案：:["vacuumtube"]第12题填空题(1分)

Mechatronicsengineeringdealswiththecombinationofmechanicalengineering,computingand____.正确答案：:["electronics"]第13题填空题(1分)

Biomedicalengineering(BME)istheapplicationof____anddesignconceptstomedicineandbiologyforhealthcarepurposes.

正确答案：:["engineeringprinciples"]第14题填空题(1分)

WilliamShockley,JohnBardeenandWalterBrattainwonthe1956NobelPrizeinphysicsfortheirinventionofthe____.正确答案：:["transistor"]第15题填空题(1分)

IEEE

istheworld’slargesttechnicalprofessionalorganization

dedicatedtotechnologyforthebenefitofhumanityin

____,computing,communicationsandotherfields.

正确答案：:["electricalandelectronicengineering"]第二章-习题第1题判断题(1分)Dependingonthemagneticleveltherearetwotypesoftransformers,stepuptransformerandstepdowntransformer._________第2题判断题(1分)Electricityistheenergymadeavailablebytheflowofelectricchargethroughaconductor.Itiscarriedbywiresorproducedby Batteryandisusedtopowermachines._______第3题判断题(1分)Ageneratorisadeviceusedtoconvertelectricalenergytomechanicalenergy.______第4题判断题(1分)Transformersstepdownthevoltageto120Vforlocaldistribution,suchashomes,offices,andfactoriesandfinallypermitthepowertobeusedsafely._______第5题判断题(1分)Dcmachinecanoperateaseitheramotororageneratorintermsofthedirectionofthepowerflowthroughit.________第6题判断题(1分)Acmachinesmainlyconsistoftwoclasses:synchronousmachinesandinductionmachines._______第7题判断题(1分)Aninductionmotorneedsdcfieldcurrenttorunthemachine.________第8题判断题(1分)Dependingontheoperatingphase,atransformercanbeeitherasinglephasetransformeroradoublephasetransformer.________第9题判断题(1分)Mostdcmachineshaveacvoltagesandcurrentswithinthem._____第10题判断题(1分)AgeneratorworksontheprincipleofFaraday’sLawofElectromagneticInduction._________第11题填空题(1分)

Whenlow-voltageAC

____isclosedorbreakingelectricloops,electricarcwillbegeneratedbetweenthecontactterminals.正确答案：:["contactor"]第12题填空题(1分)

In1832,theyearofMichaelFaraday’sdiscoverythatachanging____fieldproducesanelectricfield,ayoungFrenchengineerpatentedanewandmoreefficientwaterwheel.正确答案：:["magnetic"]第13题填空题(1分)

Theprojectisdesignedto____around30megawattsofpowerforthenationalgrid.正确答案：:["generate"]第14题填空题(1分)A

____

isapieceofelectricalequipmentwhichchangesavoltagetoahigherorlowervoltage.正确答案：:["transformer"]第15题填空题(1分)Inengineering,____combineselectricalandmechanicalprocessesandproceduresdrawnfromelectricalengineeringandmechanicalengineering.正确答案：:["electromechanics"]第16题填空题(1分)Mostoftheelectricityconsumedtodayisproducedbythreephase____generator.正确答案：:["synchronous"]第17题填空题(1分)Magneticfieldsarethefundamentalmechanismbywhichenergyis____fromoneformtoanotherinmotors,generators,andtransformers.正确答案：:["converted"]第18题填空题(1分)Electricmotorsare____,beingfoundinapplicationsasdiverseasindustrialfans,blowersandpumps,machinetools,householdappliances,anddiskdrives.正确答案：:["ubiquitous"]第19题填空题(1分)Typicalapplicationsforthismotorarevacuumcleaners,drills,similarportabletools,andkitchen____.正确答案：:["appliances"]第20题填空题(1分)Whenwemodeltherealtransformerwewillfindthattherearecircuitelementsbetweentheinputandoutput____.正确答案：:["terminals"]第三章-习题第1题填空题(1分)1.Anelectricpowersystemisanetworkofelectricalcomponentsdeployedto____electricpower.正确答案：:["supply,transfer,anduse"]第2题填空题(1分)2.Thegridcanbedividedintothefollowingparts:____.正确答案：:["thegenerators,thetransmissionsystemandthedistributionsystem"]第3题填空题(1分)3.Wecanfindspecializedpowersystemsthatdonotusethree-phaseACpowerin____.正确答案：:["aircraft,electricrailsystems,oceanlinersandautomobiles"]第4题填空题(1分)Analternatingcurrentisinfluencedbyinductance,capacitance,voltageand____.正确答案：:["resistance"]第5题填空题(1分)5.Renewableresourcesinclude____.正确答案：:["wind,hydro-power,solarenergy,marineenergy,nuclearpower,geothermalpower,biomass,etc."]第6题判断题(1分)Single-phaseelectricityoperatesonlyat50Hz.()第7题判断题(1分)CentralizedACsystemsnowusethree-phaseelectricity.()第8题判断题(1分)Three-phaseelectricityoperatesmoreefficientlythansingle-phasepower.()第9题判断题(1分)Conductorsbelongtothedistributionsystem.(

)第10题判断题(1分)Mostpowerstationscontainoneormoregenerators.()第四章-习题第1题单选题(1分)Generally,therearetwotypesofcontrolloop.Theyare__________controlandclosedloopcontrol.AadvancedloopBopenloopCscientificloopDovertloop第2题单选题(1分)Inclosedloopcontrol,thecontrolactionfromthecontrolleris_____________ofthe"processoutput".AindependentBinterdependentCdependentDintrodependent第3题单选题(1分)Theadvancedtypeofautomationthatrevolutionizedmanufacturing,aircraft,communicationsandotherindustries,is______________.AfeedbackcontrolBopencontrolCclosedcontrolDinternalcontrol第4题单选题(1分)Inthemid-19thcenturymathematicswasfirstusedtoanalyzethestabilityoffeedbackcontrolsystems.()AaccessibilityBfeasibilityCflexibilityDstability第5题单选题(1分)Since______________istheformallanguageofautomaticcontroltheory,wecouldcalltheperiodbeforethistimetheprehistoryofcontroltheory.AmathematicsBmechanicsCkineticsDhydraulics第6题判断题(1分)Automaticcontrolinengineeringandtechnologyisawidegenerictermcoveringtheapplicationofmechanismstotheoperationandregulationofprocesseswithoutcontinuousdirecthumanintervention.()第7题判断题(1分)Theopenloopcontrolisanapplicationofnegativefeedbacktoasystem.(

)第8题判断题(1分)Inclosedloopcontrol,thecontrolactionfromthecontrollerisindependentofthe"processoutput".(

)第9题判断题(1分)AFeedbackControlSystemisasystemwhichtendstomaintainaprescribedrelationshipofonesystemvariabletoanotherbycomparingfunctionsofthesevariablesandusingthedifferenceasameansofcontrol.()第10题判断题(1分)Thetheoreticalbasisofclosedloopautomationisnotcontroltheory.(

)第11题判断题(1分)ThehistoryofautomaticcontroltracesbacktoAncientGreece.()第12题判断题(1分)TheFirstWorldWarsawmajoradvancementsinthefieldofmasscommunicationandsignalprocessing.(

)第13题判断题(1分)ThomasSocratesinventedthesteamenginein1713,andthisdatemarkstheacceptedbeginningoftheIndustrialRevolution.(

)第14题判断题(1分)Athermostatisasimplenegativefeedbackcontroller.()第15题判断题(1分)Incontrolcomplexityitcanrangefromsimpleon-offcontroltomulti-variablehighlevelalgorithms.()第16题填空题(1分)Withthe____ofcloudcomputingwequicklyrealizedthatthismeteredresourceusagehadanotherimportantmanagementperspective--costing.正确答案：:["advent"]第17题填空题(1分)Thedevelopmentofmicrocomputersandautomatictechnologieshasgreatlypromotedtheintelligentfunctionsandautomatizationofindustrial____.正确答案：:["instrumentation"]第18题填空题(1分)Whenwe____thepowersupplysystemofthetown,wereckonedononetransformerperfourblocks.正确答案：:["laidout"]第19题填空题(1分)Thetransformerisdesignedto____theappliedvoltageof120V(rms)to24V(rms)at60Hz.正确答案：:["stepdown"]第20题填空题(1分)Whenwemodeltherealtransformerwewillfindthattherearecircuitelementsbetweentheinputandoutput____.正确答案：:["terminals"]第21题填空题(1分)Itprovidesserversandrun-timerstohelpyouquicklycreateand____aWebservice.正确答案：:["deploy"]第22题填空题(1分)Energyavailableinmanyformsisoften____toelectricalformbecauseelectricenergycanbetransmittedandcontrolledsimply,reliably,andefficiently.正确答案：:["converted"]第23题填空题(1分)Electricpowergeneration,transmission,____andutilizationarethefeaturesofanypracticalpowersystem.正确答案：:["distribution"]第24题填空题(1分)Thispaperanalyzesthe____changeregularitytomeasuretheconcentricityofturbogeneratorrotor.正确答案：:["deviation"]第25题填空题(1分)Ifthe____nominalvaluesarenotreached,thecoolingsystemmustbecheckedforleaksandrepaired.正确答案：:["prescribed"]第26题填空题(1分)____referstoaclassofcrystallinesolidswithelectricalconductivitybetweenthatofaconductorandaninsulator.正确答案：:["semi-conductor"]第27题填空题(1分)The____reducedthesizeofthecomputer,thuscreatinganewgenerationofportableminicomputers.正确答案：:["integralcircuit"]第28题填空题(1分)Thereisacapacitancebetweenanytwoconductorswhichareseparatedbya(n)____(airorvacuum).正确答案：:["dielectric"]第29题填空题(1分)Toavoid____shockorfaultyconnections,donotworkwiththeelectricalpartsunlessyouareaqualifiedelectrician.正确答案：:["electrical"]第30题填空题(1分)Theobjectiveistoobtainfromasubstancebychemicalormechanicalaction,asbypressure,distillation,or____.正确答案：:["evaporation"]第五章-习题第1题填空题(2分)

Power

electronicstechnologyisthetechnologyassociatedwithefficient

conversion,controlandconditioningofelectricpowerfromits

available____intothedesirableelectrical____form.正确答案：:["input"]正确答案：:["output"]第2题填空题(1分)

In

termsofworldhistory,powerelectronicsisa____science.正确答案：:["young"]第3题填空题(1分)

A

keytopowerelectronicstechnologywastheinventionofthe

____amplifierbyH.S.Blackin1927.正确答案：:["feedback"]第4题填空题(1分)

The

firstelectronicsrevolutionbeganin1948withtheinventionofthe

____byAmericanscientistsJ.Bardeen,W.H.Shockleyfrom

“BellLabs”.正确答案：:["transistor"]第5题填空题(1分)

Before

the1960s,semiconductorengineeringwasregardedaspartof

____andlow-voltageelectronicengineering.正确答案：:["low-current"]第6题填空题(1分)

In

hybridelectricvehicles,powerelectronicsareusedintwoformats:

____hybridandparallelhybrid.正确答案：:["series"]第7题填空题(1分)

An

electriccarisanautomobilethatispropelledbyoneormore

electricmotors,usingelectricalenergystoredin____

batteriesoranotherenergystoragedevice.正确答案：:["rechargeable"]第8题填空题(1分)

When

thefootisliftedfromtheacceleratorofaninternalcombustion

engine,engine____causesthecartoslow.正确答案：:["braking"]第9题填空题(1分)

Variants

suchaslithiumironphosphateandlithium-titanateattempttosolve

the____issueswithtraditionallithium-ionbatteries.正确答案：:["durability"]第10题填空题(1分)

As

ofDecember2013,Estoniaisthefirstandonlycountrythathad

deployedanelectricvehicle____networkwithnationwide

coverage.正确答案：:["charging"]第11题判断题(1分)

The

lifeofthevacuumtubecouldstillgoonevenifitsfilamentburns

out.第12题判断题(1分)

Development

ofacommercialthyristorranthesecondelectronicsrevolution.第13题判断题(1分)

The

differencebetweenaserieshybridandaparallelhybridisthe

relationshipoftheelectricmotortotheinternalcombustion

engine.第14题判断题(1分)

Devices

usedinelectricvehiclesconsistonlyofDC/DCconvertersfor

batterychargingandDC/ACconverterstopowerthepropulsion

motor.第15题判断题(1分)

Cars

withaninternalcombustionenginearearound3timesasefficient

aselectricmotors.第16题判断题(1分)

The

energycrisesofthe1970sand1980sbroughtalong-terminterestin

electriccars.第17题判断题(1分)

Electric

carsmakesignificantlybiggernoisethanconventionalinternal

combustionengineautomobiles.第18题判断题(1分)

Lithium-based

batterieshavealimitedshelfandcyclelifetime.第19题判断题(1分)

Most

carswithinternalcombustionenginescanbeconsideredtohave

indefiniterange,astheycanberefueledveryquickly.第20题判断题(1分)

Most

vehiclescannotsupportmuchfastercharging,evenifasuitable

powersupplyisavailable.第六章-习题第1题多选题(2分)Whataretheprinciplesandcriteriaforselectingproperinsulators?()AgoodthermalcharacteristicsBcostChighheatresistanceDotherfactors正确答案：ABCD第2题多选题(2分)Whatarethedisadvantagesofairasaninsulator?()ASurfaceneedremaincleanandfreeofdustoverlongperiodsBlowcostCunrepairableDpoordielectricstrength正确答案：AD第3题多选题(2分)Whataretheadvantagesofepoxy?()AgoodthermalcharacteristicsBlowcostCexcellentadhesionDrepairable正确答案：AC第4题多选题(2分)Whataretheshortcomingsofperfluorinatedliquids?()AcolorlessBunrepairableChighexpenseDevaporation正确答案：CD第5题多选题(2分)Whatarethedisadvantagesofsilicone(two-part)encapsulation?()ApooradhesionBbadthermalconductivityChighexpenseDpoordielectricstrength正确答案：AB第6题判断题(1分)Precautionsarenotneedediftherearenomorethan230kilovolts.()第7题判断题(1分)Theinsulatingmaterialshouldnotbehomogeneous.(

)第8题判断题(1分)Epoxyareunrepairable.()第9题判断题(1分)Lowexpenseisadisadvantageofair.(

)第10题判断题(1分)Evaporationreferstoamechanicalactiontomakeobjectivestochangefromliquidtogas.()第11题判断题(1分)SF6isacolorlessandodorlessgasandextremelysafeifsomeonebreathesin.(

)第12题判断题(1分)Oilcanbecomecontaminatedeasilybyarcingandwiththeformingofforeignmaterials.()第13题判断题(1分)Whenthereareinjuries,theelectricitywillpenetratetheskinmoreslowly.(

)第14题判断题(1分)Pooradhesionisperhapsthebiggestshortcomingandcanbealleviatedbypreparingthesurfaceproperly.()第15题判断题(1分)Currentsthatmightgenerallybethoughtofasratherweakcanbeconsidereddangerousiftheyarecoursingthroughsomerawcables.()第16题填空题(1分)OnedifficultywithusingSF6isthatthehousingmustbehermeticallys(____).正确答案：:["sealed"]第17题填空题(1分)Undesiredorunintendedelectric

a(____)

canhavedetrimentaleffectsonelectricpowertransmission,distributionsystemsandelectronicequipment.正确答案：:["arching"]第18题填空题(1分)Poora(____)isperhapsthebiggestshortcomingofsilicones.正确答案：:["adhesio"]第19题填空题(1分)Thed(____)mustbeagoodelectric

insulator

soastominimizeanyDCleakagecurrentthroughacapacitor.正确答案：:["dielectric"]第20题填空题(1分)Inrecentyears,the3Dmodelsofthedriveaxleh(____)caneasilybeestablishedwiththesoftwareinthecomputer.正确答案：:["housing"]第21题填空题(1分)A(n)e(ncapsulant)isdesignedtoelectricallyi____andenvironmentallyprotectproductssuchas

printedcircuitboards

frommoisture,chemicals,mechanical/thermalshockandvibration.

正确答案：:["insulate"]第22题填空题(1分)Wehavetakeneveryp____toprotectusfromCOVID-19.正确答案：:["precaution"]第23题填空题(1分)Heatdoesnotscatterasreadilyaslight,sothethermalenergycanp____throughtheenamel,exposingchangesincomposition.正确答案：:["Penetrate"]第24题填空题(1分)Itiswidelyknownthatunderthesamemaxsharerate,theareaoft(____)loopdecreaseswiththeincreasingofthetimeofsharerate.

正确答案：:["thixotropic"]第25题填空题(1分)Ifappliedtohumanskin,50voltscancausethehearttof____.正确答案：:["fibrillate"]第七章-习题第1题填空题(1分)Withthechangeoverfrom____todigitalTVsignalslessthanamonthaway,manyofusarelookingatTVupgradestomatch.正确答案：:["analog"]第2题填空题(1分)Anyinterferenceatfrequenciesoutsidethesignalbandcanbeeliminatedbyappropriate____.正确答案：:["filtering"]第3题填空题(1分)Theperformanceofaninductionmotorcanbecharacterizedbysuchfactorsasefficiency,powerfactor,startingtorque,startingcurrent,____torque,andmaximuminternalpowerdeveloped.正确答案：:["pull-out"]第4题填空题(1分)The____(inputprocessor)convertstheelectricsignalintoaformthatissuitablefortransmissionthroughthephysicalchannelortransmissionmedium.正确答案：:["transmitter"]第5题填空题(1分)Ifyouactuallycombinethebestideasofboth,youendupwithanextensible,

()____andlooselycoupledsystem.正确答案：:["modular"]第6题填空题(1分)Youcancausesignificanthardwaredamagetoyourcomputerifsignalsofexcessive____areconnectedtothesoundcard’smicrophoneinput.正确答案：:["voltage"]第7题填空题(1分)Theeffectofsignal____istoreducetheamplitudeofthedesiredsignals(t)and,thus,torendertheinformation-bearingsignalmorevulnerabletoadditivenoise.正确答案：:["attenuation"]第8题填空题(1分)Devicesthatconvertcontrolsignalsfromoneformtoanotherareknownas____,mostofwhichhaveanoutputsignalintheformofelectricenergy.正确答案：:["transducers"]第9题填空题(1分)

Certain

materials,called____,allowelectronstoflowthroughthem.正确答案：:["conductors"]第10题填空题(1分)

A(n)

____systemisoneinwhichtwoormoresignalsaretransmitted

jointlyoverthesametransmissionchannel.正确答案：:["multiplexing"]第11题填空题(1分)

The

____fromtheseparallelgeneratorswilladduptomakeatotal

flowof500amperes.正确答案：:["current"]第12题填空题(1分)

The

heartofanycommunicationsystemconsistsofthreebasicelements:

transmitter,transmissionmediumorchanneland____.正确答案：:["receive"]第13题填空题(1分)

Bluetooth

isa____technologystandardforexchangingdataovershort

distancesfromfixedandmobiledevices,andbuildingpersonalarea

networks.正确答案：:["wireless"]第14题判断题(1分)Inthephysicalworld,anyquantityexhibitingvariationintimeorvariationinspace(suchasaimage)ispotentiallyasignal.()第15题判断题(1分)Signalprocessing,abranchofelectronicengineering,isaenablingtechnologythatmodelsandanalyzesdatarepresentationsofinformation.()第16题判断题(1分)Signalprocessingtechnologyincludestwomainsubfields:analogsignalprocessinganddigitalsignalprocessing.()第17题判断题(1分)Traditionaltelephoneusesdigitalsignals.()第18题判断题(1分)“Analog”indicatessomethingthatismathematicallyrepresentedasasetofdifferentvalues.()第19题判断题(1分)Digitalsignalprocessing()istheuseofdigitalprocessing,suchasbycomputers,toperformawidevarietyofsignalprocessingoperations.()第20题判断题(1分)Everytelephone,smartornot,reliesheavilyonaudioprocessingtechniquestomakecommunicationbetweentwo(ormore)peoplepossible.()第21题判断题(1分)Speechrecognitionisavitalapplicationofsignalprocessingandislikelytheeasiesttounderstand.()第22题判断题(1分)Withoutsignalprocessing,moderndigitalassistants,suchasSiri,GoogleNow,andCortana,wouldnotbeabletorecognizeauser’svoice.()第23题判断题(1分)Thesignalconditioningcircuitryhasthefunctionsofsignalamplification.()第八章-习题第1题判断题(1分)Theworldwideelectricalandelectronicsindustryisthemostflourishingandextremelydiversifiedsectorwhichhasbeengrowingatarapidpace,andatthesametimeitisalsopromotedbyanever-increasingcustomerinclination.()第2题判断题(1分)Theonlyemphasisofallelectricaltechnologytrendsistoderiveunmatchedefficiency.()第3题判断题(1分)Accordingtotheresearch,probablyinthefuture,asortofnewsolarconcentratorwouldbemoreefficientthanthecontemporaryonesanditcanbringhugeamountofsolarlighttothesolarcellsbytrackingthesun.()第4题判断题(1分)Incomingyears,thesmartopticalmicrochip,whichissettoutilizeacompleteandunorthodoxfunctionalsystem,canrunbothbyelectricityandbythelight.()第5题判断题(1分)Thewirelessenergytransmitterwouldbeabletorechargeallkindsofelectronicdeviceswithoutcominginactualphysicalcontactofthesedevices.(

)第6题判断题(1分)Differentfromtheconventionaltrains,themaglevtrainsarecompletelysecure,withoutanyseriousinjuries.()第7题填空题(1分)Becauseofthediscoveryofthedielectricsusceptibility,theengineerswillbeabletomakesomeultra-equippedandhighly____technologicalandelectronicdevices.正确答案：:["sensitive"]第8题填空题(1分)Entanglement,auniquefeatureofquantumphysics,iswellsettobeusedinfuture____.Itissaidtobemoreefficientandaccuratethanthoseofmanydetectionsystemsavailablethesedays.正确答案：:["detectionandimagingsystems"]第9题填空题(2分)AccordingtoTextA,themicrobatteriescouldbeonlyhalfthesizeofahuman____.

Interestingly,thesewouldbemadeof_____.正确答案：:["cell"]正确答案：:["viruses"]第10题填空题(1分)Thesmartopticalmicrochipmay“automaticallyprocesssignalsflowingthroughfiber-opticnetworks,withoutusingany____power”.正确答案：:["electrical"]第11题填空题(1分)Newanalogcircuitsaresaidtobemoreuser-friendlyandpowerefficientastheyarewellequippedtohandle____inamuchbetterway.正确答案：:["voltages"]第12题填空题(1分)Thewirelessenergytransmitterworksfromafewmetersawaybysurroundingthedevicesmakinga____insteadoftransmittingelectromagneticwaves.正确答案：:["non-radioactiveelectromagneticfield"]第13题填空题(1分)Afewcountriesareusingpowerfulelectromagnetstodevelophigh-speedtrains,calledmaglevtrains.Maglevisshortfor____,whichmeansthatthesetrainswillfloatoveraguidewayusingthebasicprinciplesofmagnetstoreplacetheoldsteelwheelandtracktrains.正确答案：:["magneticlevitation"]第14题填空题(2分)Thebasicprinciplebehindelectromagneticpropulsionisthat____attractand____repeleachother.正确答案：:["oppositepoles"]正确答案：:["likepoles"]第15题单选题(1分)Whichofthefollowingisnottrue?()AIII-Vcompoundsemiconductors,specifiedascompositematerials,arethelatestonesandcansqueezethesizeofexistingtransistorstoanunbelievablesmallersize.BTheelectronstravelmanytimesfasterinsiliconthantheycouldtravelinthesecompositematerialssuchasInGaAs.CIndiumgalliumarsenideisoneofthosecompositematerialswhichallowtheelectronstomoveattheirfastest.DAnInGaAstransistorisnotmorethan60nanometersanditiscapableofcarryingmorecurrent.第16题单选题(1分)Whichofthefollowingwillbeanewformoftransportationthatcouldrevolutionizetransportationofthe21stcenturythewayairplanesdidinthe20thcentury?()AconventionaltrainsBmaglevtrainsCbusesDboats第17题单选题(1分)Whycanmaglevtrainsreachunprecedentedgroundtransportationspeeds?()ABecauseofthelackoffri