模拟电子技术基础（西安邮电大学）知到智慧树期末考试答案题库2025年西安邮电大学

模拟电子技术基础（西安邮电大学）知到智慧树期末考试答案题库2025年西安邮电大学WhyisthearrowontheBJTschematicsymbolimportant?（

）

答案:ItidentifiestheemitterterminalandthetypeofBJT.Whyisdesignforaspecificbiaspointdesirableformostamplifiers?

（

）

答案:Tomeetmanufacturersuggestedopeningpoint.

；Itallowsoptimumacoperationofthecircuit.

；Itallowsoptimumdcoperationofthecircuit.Whichtypeofop-ampcircuithasunitygain,nophaseinversion,highinputimpedance,andlowoutputimpedance?

（

）

答案:voltagebufferWhichtransistoramplifierconfigurationisthemostcommonlyused?

（

）

答案:common-emitterWhichtransistoramplifierconfigurationhasa180°voltagephaseshiftfrominputtooutput?

（

）

答案:common-emitterWhichofthefollowingstatementsistrue?（

）

答案:Op-ampsarehigh-gaindcamplifiers；Op-ampshaveextremelyhighinputimpedance.；Op-ampshaveextremelylowoutputimpedance.Whichofthefollowingisnotacommonlyusedsemiconductormaterial'?（

）

答案:leadWhichofthefollowingexpressionsistrue?（

）

答案:Whichofthefollowingexpressionsistrue?（

）Whichofthefollowingcircuitsisusedtoeliminateaportionofasignal?（

）.

答案:ClipperWhichofthefollowingcircuitsisusedtochangethedcreferenceofasignalwithoutchangingtheshapeofthesignal?

(

)

答案:a

clamperWhichofthefollowingbiasingcombinationsisnotnormallyassociatedwithoneofthethreetransistoroperatingregions?（

）

答案:E-Bjunction=reverse,C-Bjunction=forwardWhichofthefollowingbiasingcircuitscanbeusedwithE-MOSFETs?

（

）

答案:drain-feedbackbiasWhichofthefollowingarepropertiesoflogarithms'?（

）

答案:Whichofthefollowingarepropertiesoflogarithms'?（

）Whichofthefollowingarepropertiesoflogarithms?（

）

答案:Whichofthefollowingarepropertiesoflogarithms?（

）Whentestedwithanohmmeter,adiodeshouldhavearelativelysmallresistancefor(

)condition.

答案:theforward-biasedWhendesigningforbestbiasstabilitythe（

）

configurationshouldbechosen.

答案:voltage-dividerbiasWhendesigningavoltage-dividerbiascircuit,thedividerresistors（

）.

答案:shouldcarryapproximatelyequalcurrent；shouldcarrycurrentsthatare10timesthebasecurrent；determinethebasevoltageasthedropacrossbase-commonresistorWhenatransistorisinsaturation,thetotalcollectorcurrentislimitedby（

）.

答案:collectorsupplyvoltageandthetotalresistanceinthecollectorandemittercircuitsWhenap-njunction'sdepletionlayerisnarrowedandthedeviceactsasanearlyperfectconductor,itis（

）.

答案:forward-biasedWhenap-njunctionisreverse-biased,thedepletionlayeris________andthedeviceactsasanear-perfect________（

）.

答案:widened;insulatorWhenap-njunctionisreverse-biased,itsjunctionresistanceis

（

）.

答案:highWhenagivenop-amphasacommon-modeinputof10V,theoutputofthedeviceis10V.

Whenthedevicehasadifferentialinputof2mV,theoutputofthedeviceis10V.WhatistheCMPRofthedevice?（

）

答案:5000:1Whenadiodeisdopedwitheitherapentavalentoratrivalentimpurityitsresistancewill（

）

.

答案:decreaseWhenaBJTtransistorisusedinaswitchingcircuit,itoperatesinthe（

）.

答案:saturationandcutoffregionsWhenaBJTisbiasedinthecutoffregionthecollector-to-emittervoltageistypicallyequalto（

）.

答案:thecollectorsupplyvoltageWhenaBJTisbiasedinthecut-offregion,itsbase-emitterjunctionis________-biasedanditscollector-basejunctionis________-biased.（

）

答案:reverse;reverseWhenaBJThasitsbase-emitterjunctionreversebiasedanditsbase-collectorjunctionforwardbiased,itisbiasedinthe（

）.

答案:cutoffregionWhenaBJThasitsbase-emitterjunctionforwardbiasedanditscollector-basejunctionreversebiased,itisbiasedinthe（

）.

答案:activeregionWhenaBJThasitsbase-emitterjunctionforwardbiasedanditscollector-basejunctionalsoforwardbiased,itisinthe（

）.

答案:saturationregionWhattwoparametersrepresenttheFETtransfercharacteristic?（

）

答案:gate-to-sourcevoltageanddraincurrentWhatisthevalueofthevoltagedroppedacrossforward-biasedsilicondiodesthatareconnectedinparallelwitheachother?

（

）.

答案:0.7VVoltage-seriesfeedback（

）

theoutputimpedanceofanop-amp.

答案:decreasesVoltage-seriesfeedback（

）

theinputimpedanceofanop-amp.

答案:increasesVoltage-dividerbiasstabilityis（

）.

答案:independentofbetaTypicaldifferentialamplifiercircuitchangesfromdouble-endedoutputtosingle-endedoutput,differential-modevoltagegain（

）.

答案:decreaseTypicaldifferentialamplifiercircuitchangesfromdouble-endedinputtosingle-endedinput,differential-modevoltagegain（

）

.

答案:unchangedTypicaldifferentialamplifiercircuitchangesfromdouble-endedinputtosingle-endedinput,common-modevoltagegain

（

）.

答案:unchangedTransistorcircuitsthatarequitestableandrelativelyinsensitivetotemperaturevariationshave（

）.

答案:largebetasTheZenerdiodemustbeoperatedsuchthat（

）.

答案:AlloftheseThevoltagegainofaverywell-designedcommoncollectoramplifierconfiguration,usingapnptransistor,is（

）.

答案:intherange0.95to0.99Thevoltagefollowertypicallyhasavoltagegainvalueof（

）.

答案:1Thevalueofgate-to-sourcevoltagethatcausesthedraincurrenttoreachitsmaximumvalueatagivenvalueofdrainvoltageiscalled（

）.

答案:Thevalueofgate-to-sourcevoltagethatcausesthedraincurrenttoreachitsmaximumvalueatagivenvalueofdrainvoltageiscalled（

）.ThetwoinputvoltagesofthedifferentialamplifierareUi1=0.04V,andUi2=0.08V,thecommonmodeinputvoltage

（

）.

答案:0.06VThetransitioncapacitanceofadiodeisashuntcapacitiveeffectthatoccurswhenthediode（

）.

答案:isreverse-biasedThetermsemi-logreferstoagraphicalscalethathas（

）.

答案:alinearaxisandalogaxisThetermquiescentmeans（

）.

答案:inactiveTheself-biasconfigurationdevelopsthecontrollinggate-to-sourcevoltageacrossaresistorintroducedinthe（

）.

答案:sourcelegTheroll-offrateofasecondorderfilteris（

）.

答案:40dB/decadeor12dB/octaveThereversesaturationcurrentofadiodewilljustabout（

）forevery10°Criseinthediodetemperature.

答案:doubleTheregionoftheJFETdraincurvethatliesbetweenpinch-offandbreakdowniscalled（

）.

答案:thesaturationregionTheprimarydifferencebetweenJFETsanddepletion-typeMOSFETsis（

）.

答案:TheprimarydifferencebetweenJFETsanddepletion-typeMOSFETsis（

）.Thepowerthatanamplifierdeliverstoaloadisequaltothedifferencebetweenthepowerthatthecircuitdrawsfromthepowersupplyandthepowerthatthecircuitdissipates.（

）

答案:对Thepointofintersectionbetweenthecharacteristiccurveofthediodeandtheresistorsloadlineisknownasthe(

).

答案:All

oftheseThepiecewiselinearmodel,equivalentcircuitofthediodeconsistsof（

）.

答案:abattery,asmallresistor,andtheidealdiodeTheoutputimpedanceofcurrent-shuntfeedbackamplifier（

）

theoutputimpedanceofitsop-amp.

答案:isincreasedwhencomparedtoTheoutputimpedanceofaBJTis（

）.

答案:resistiveTheoutputimpedanceofaBJTamplifiertendstobemuchlessthanthatofacomparableFETamplifier.（

）

答案:错Theoperationalamplifierwillonlyslightlyamplifysignals（

）.

答案:thatarecommononboththeinputsTheop-ampcircuitthathasacapacitorasthefeedbackcomponentiscalleda(n)___B___.

答案:integratorThemaximumtheoreticalefficiencyofanRC-coupledclassAamplifieris（

）.

答案:25%ThemaximumcurrentinaJFETisdefinedasIDSSandoccurswhenVGSisequalto（

）.

答案:zeroVoltsThelow-frequencyresponseofaBJTamplifierisaffectedby（

）.

答案:thecouplingandbypasscapacitorvaluesThelevelofdrain-to-sourcevoltagewherethetwodepletionsregionsappeartotouchisknownas（

）.

答案:pinch-offTheJFETisa（

）.

答案:voltage-controlleddeviceTheinvertingandnoninvertinginputstoanop-ampareusedtodrivea(n)（

）

amplifier.

答案:differentialTheinputresistanceofastabilizedfixed-biascircuitconfigurationis（

）.

答案:directlyrelatedtotheemitterresistorTheinputpowertoadeviceis5000Wat400V.Theoutputpowerofthedeviceis750W,andtheoutputimpedanceis25Ω.Calculatethevoltagegainindecibels.（

）

答案:-9.311dBTheinputpowertoadeviceis5000Wat400V.Theoutputpowerofthedeviceis750W,andtheoutputimpedanceis25Ω.Calculatethepowergainindecibels.

（

）

答案:-8.239dBTheinputimpedanceofavoltage-shuntfeedbackamplifier（

）

theinputimpedanceofitsop-amp.

答案:isdecreasedwhencomparedtoTheinputimpedanceofaFETamplifiertendstobemuchgreaterthanacomparableBJTamplifier.（

）

答案:对Theinputimpedanceofacommon-emitterconfigurationistypically(

).

答案:between300Ωand10kΩTheinputimpedanceforacommon-emitterconfigurationcanbeexpressedas(

).

答案:Theinputimpedanceforacommon-emitterconfigurationcanbeexpressedas(

).TheinputcurrentforaFETamplifierisgenerallyassumedtobezero.（

）

答案:对Theidealdiodesymbolhasanarrowthatpointsinthedirectionof（

）.

答案:theforwardcurrentflowThegainindecibelsofapowergainof10,000,000is（

）.

答案:70dBTheFETversionoftheBJT'scommon-emitterconfigurationisthe（

）

circuit.

答案:common-sourceTheenhancement-typeandthedepletion-typeFETsaresubclassesof（

）.

答案:metal-oxide-semiconductorFETsTheemitter-followerconfigurationhas（

）.

答案:NotatallTheelectrodewithn-typematerialofadiodeiscalledthe(

).

答案:cathodeThedifferencebetweentheresultingequationsforanetworkinwhichannpntransistorhasbeenreplacedbyapnptransistoris（

）.

答案:thesignassociateswiththeparticularquantitiesThedepletion-typeMOSFET'hasspecificationsandmanycharacteristicsthataresimilartothe（

）.

答案:JFETThedepletiontypeofMOSFETcanoperateinthe（

）.

答案:inthedepletionmodeandtheenhancementmodeThecrossoverdistortioninaclassBamplifierispreventedby（

）.

答案:biasingthetransistorsjustslightlyabovecutoffTheconditionwhereincreaseinbiascurrentwillnotcausefurtherincreasesincollectorcurrentiscalled（

）.

答案:saturationThecommon-emitter,forward-current,amplificationfactorisbetterknownas（

）.

答案:acβThecommon-emitteramplifierhas（

）.

答案:voltagegain,currentgain,andpowergainThecommon-base,short-circuit,amplificationfactorisbetterknownas（

）.

答案:acαThecommon-baseamplifierischaracterizedashavingarelatively________inputimpedanceandrelatively________outputimpedance.

（

）

答案:low;highTheCMRRofaninvertingamplifieralwayslowerthanthatofitsop-ampbecause（

）.

答案:thevalueofdifferentialgainforaninvertingamplifierislowerthanthatofitsop-ampThecharacteristicofanidealdiodearethoseofaswitchthatcanconductcurrent（

）

.

答案:inonedirectiononlyThebandwidthofanamplifieris（

）.

答案:Thebandwidthofanamplifieris（

）.Theapproximationthatallowssuperpositiontobeusedtoisolatetheacanalysisandthedcanalysisofsmall-signalamplifiersisthatthecircuitresponseis（

）.

答案:linearTheanalysisthatwemostlyworkwithisthatofthen-channeldevice.Forp-channeldevicesthetransfercurveemployedisthe________imageandthedefinedcurrentdirectionsare________.

（

）

答案:mirror;reversedTheactofgivingofflightbyapplyinganelectricalsourceofenergyiscalled(

).

答案:electroluminescenceThe（

）

marginisdefinedasthenegativeofthevalueof|AF|decibelsatthefrequencyatwhichthephaseangleis180°.

答案:gainThe（

）

FETamplifierhaslowinputimpedance,highoutputimpedance,andhighvoltagegain.

答案:common-gateThe（

）

amplifierhashighinputimpedance,lowoutputimpedance,andlowvoltagegain.

答案:common-drainThe（

）

terminaloftheJFFTistheequivalentofthecollectorterminalofaBJT.

答案:drainThe（

）

terminaloftheJFETistheequivalentofthebaseterminalofaBJT.

答案:gateThe（

）

JFETusesapositivedrainsupplyvoltage.

答案:n-channelSilicondiodeshavebeenmoresignificantlydevelopedthangermaniumbecause

(

).

答案:itischeaperShockley'sequationdefinesthe（

）

oftheFETandareunaffectedbythenetworkinwhichthedeviceisemployed.

答案:transfercharacteristicsPoweramplifiersaretypicallyusedtodrivelowimpedanceloads.（

）

答案:对Pentavalentatomsareoftenreferredtoas(

).

答案:donoratomsNegativedBvaluesrepresent（

）.

答案:powerlossesNegativecurrentfeedback（

）.

答案:Negativecurrentfeedback（

）.MOSFETstypicallyhaveaninputimpedancevaluethatis（

）.

答案:higherthantheJFETManyMOSFETdevicesnowcontaininternal（

）

thatprotectthemfromstaticelectricity.

答案:ZenerdiodesIncreasingthetemperatureofaforward-biaseddiode

（

）.

答案:causesforwardcurrenttoincreaseInthesaturationregion,thebase-emitterjunction（

）.

答案:andthebase-collectorjunctionsarebothforward-biasedInthefamilyofFETs,youcanexpecttofind

（

）.

答案:an

n-channeltype；a

p-channeltype；unipolarstructureInthedesignofanemitter-biasstabilizedcircuitengineering,judgmentmustbeusedbecausethe（

）.

答案:NotatallInthecut-offregion,thebase-emitterjunction（

）.

答案:andthebase-collectorjunctionsarebothreverse-biasedIntheactiveregion,thebase-emitterjunction

（

）.

答案:isforward-biasedwhilethebase-collectorjunctionisreversed-biasedInmostcases,whichtwoofthethreeBJTterminalcurrentsareapproximatelyequalinvalue?（

）

答案:emittercurrentandbasecurrentInaself-biascircuitforann-channelJFETtransistorthese1f-biasline（

）.

答案:isslantedandpassesthroughoriginImpedancematchingisimportantfor（

）.

答案:maximumpowertransferfromsourcetoloadIftheresistorintheemitterlegisnotbypassedbyacapacitorthenthevoltagegainofthesmallsignalamplifierwill（

）.

答案:decreaseIftheresistorintheemitterlegisnotbypassedbyacapacitorthentheinputimpedanceofthesmallsignalamplifierwill（

）.

答案:increaseIftheresistorbypasscapacitorinthesourcelegisremoved,thevoltagegainofthesmallsignalFETamplifier(

).

答案:willdecreaseIfseveralidenticalstagesofamplifiers,eachhavingtheexactsameupperandlowercutofffrequencies,areconnectedincascade,thenthebandwidthoftheresultingamplifierwill（

）.

答案:decreaseIfonesilicondiodeandonegermaniumdiodeareconnectedinseries,thevoltagedropacrossthecombinationofthetwodiodeswillbeequalto(

).

答案:theforwarddropequaltothatofthesumofthevoltagedropsacrossthetwodiodesHowmanyfeedbackresistorsarefoundina3-inputvoltagesummingcircuitthatisconstructedaroundanop-amp?

（

）

答案:1Holesarethemajoritycarriersinap-typematerial.(

)

答案:对Generally,itisgooddesignpracticeforlinearamplifierstohaveoperatingpointsthatcloseto（

）.

答案:themidpointoftheloadlineForlevelsofgate-to-sourcevoltagegreaterthanthethresholdvoltage,thedraincurrentisdirectlyrelatedtothe（

）.

答案:squareofthedifferencebetweenthegate-to-sourcevoltageandthethresholdvoltageForbasicoperationofatransistorthebase-emitterjunctionis（

）

biased.

答案:forward-Foratwo-portsystem,likeaBJTamplifier,theno-loadvoltagegain（

）.

答案:isalwaysgreaterthantheloadedvoltagegainForagate-to-drainvoltagelessthanthethresholdlevelthedraincurrentofanenhancement-typeMOSFETis（

）.

答案:100mAFETsusually（

）.

答案:arelesssensitivetotemperaturechangethanBJTs；haveahigherinputimpudencethanBJTs；aresmallerinconstructionthanBJTsDopingisusedto

（

）.

答案:increasetheconductivityofanintrinsicsemiconductorDependingontheconfigurationoftheamplifier,themagnitudeoftheno-loadvoltagegainforasingleBJTtransistoramplifiertypicallyrangesfrom（

）.

答案:justalittlelessthan1toafewhundredDependingontheconfigurationoftheamplifier,themagnitudeoftheno-loadcurrentgainforasingleBJTtransistoramplifiertypicallyrangesfrom（

）.

答案:justalittlelessthan1toalevelthatmayexceedonehundredCurrent-seriesfeedback（

）theoutputimpedanceofanop-amp.

答案:hasnoeffectonCrossoverdistortioninclassBamplifiersispreventedby（

）.

答案:biasingthetransistorsslightlyabovecutoffCMRRisamaintechnicalindexofdifferentialamplifiercircuit,reflects

（

）theabilityofamplifiercircuit.

答案:EnlargingDifferentialModeandSuppressingCommonModeCMOSstandsfor（

）.

答案:complementaryMOSClassDamplifiershaveamaximumtheoreticalefficiencyof（

）.

答案:over90%CalculatethevoltagegainforvoltageseriesfeedbackwhentheamplifiergainisA=-2000andF=-1/50.

（

）

答案:-48.78CalculatethegainofanegativefeedbackamplifierhavingA=1000andF=0.099.（

）

答案:10BJTsarecommonlyusedas（

）.

答案:theprimarycomponentsinamplifiersAsthedevicetemperatureincreases,semiconductormaterialstendtohave

（

）.

答案:anincreasingnumberoffreeelectronsAnop-ampbandpassactivefilterprovidesaconstantoutput（

）.

答案:Anop-ampbandpassactivefilterprovidesaconstantoutput（

）.AninvertingamplifierandanoninvertingamplifierarebuiltusingthesamevaluesofRfandR1.Assumingthattheop-ampsbeingusedinthetwocircuitshaveidenticalcommon-modegainvalues,（

）.

答案:thenoninvertingamplifierhasthehigherCMRRAnamplifierhasamidbandpowergainof24,500.WhatisthevalueofthepowergainindBforthecircuit?（

）

答案:43.9dBAnamplifierhasagain-bandwidthproductof200MHz.Afeedbacknetworkisaddedthathasafeedbackfactor(1+βA)of18.88.Whatisthegain-bandwidthproductforthecircuitwiththeaddedfeedbacknetwork?（

）

答案:200MHzAmplifieracinputandoutputcurrentsare（

）.

答案:alwaysinphaseAddinganegativevoltage-feedbacknetworktoanamplifierhasnoeffectonthevalueof（

）forthecircuit.

答案:inputimpedance；frequencyresponse；signaldistortionAtransistoramplifierhasaninputsignalappliedtoitsemitterterminalandanoutputsignaltakenfromitscollectorterminal.Theamplifierisa(n)（

）.

答案:common-baseamplifierAsummingintegratorisanop-ampintegratorthathas（

）.

答案:multipleinputresistorsandfeedbackcapacitorsAsecondorderlow-passfilterhasahigh-endroll-offof（

）.

答案:40dB/decadeAp-njunctionisforwardbiasedwhen（

）.

答案:theappliedpotentialcausesthe

n-typematerialtobemorenegativethanthe

p-typematerialAmajordisadvantageofMOSFETsis（

）.

答案:thatitissensitivetoelectrostaticdischargesAJFETcanbebiasedinseveraldifferentways.Thecommonmethod(s)ofbiasingann-channelJFETis(are)（

）.

答案:self-biasconfiguration；voltage-dividerbiasconfiguration；fixed-biasconfigurationAgivenBJT,β=400.Whatisthevalueofαforthedevice?（

）

答案:0.9975AgivenBJThasanemittercurrentof15mAandacollectorcurrentof14.95mA.Whatistheexactvalueofβ?（

）

答案:299AgivenBJThasanalphaof0.9985andacollectorcurrentof15mA.Whatisthevalueofbasecurrent?

（

）

答案:NotallrightAgainof7isrequiredfromanoninverting