雨课堂学堂在线学堂云《Electrical Test（重庆水利电力职业技术学院）》单元测试考核答案

第1题

Whichofthefollowingmaterialsisnotadielectric?

AtapwaterBairC

transformeroil

DSF6第2题Electricalequipmentproducesinsulationperformance()deterioration,structuregraduallydamagedphenomenon,knownasdielectricaging.()Areversible

B

irreversible

Crandom

Duncertain第3题Whichofthefollowingtestsisanon-destructivetest?AInsulationresistancetest

BACwithstandvoltagetesC

DCwithstandvoltagetestD

Impactwithstandvoltagetest第4题Withtheincreasingvoltagelevelofthepowersystem,insulationbecomestheweaklinkinelectricalequipment.第5题Therelativedielectricconstantistheratioofthegeometriccapacitancewhenfilledwithamediumandtheelectrostaticcapacitancewheninavacuum.第6题

Dipoletypepolarizationhasnoenergyloss,sandwichtypepolarizationhasenergyloss第7题Thesizeofthedielectricconductanceisindependentofthe()ofthechargedmassA

densityBspeedCchargeDhumidity第8题Whichofthefollowingmediaisnotahydrophobicitymedium?

A

glassB

paraffinCpolystyreneDsiliconeorganics第9题

Theinsulationresistanceofadielectric()withtemperaturerisesAdecrease

B

increaseC

unchanged

Duncertain第10题

Alossymediumcanberepresentedbyanidealcapacitorwithoutlossesandaneffectiveresistanceinparallelorseries第11题TheactivepowerlossofthedielectricatDCvoltageisthedielectricloss.

第12题

Thefreeingcausedbythe()stateofthegasmoleculesiscalledthermalionization.AcollisionmovementBthermalmovementC

lightirradiationDstrong

electricfield第13题

Whentheelectricfieldstrengthofthegasreachesacertainvalue,thecurrentinthegasincreasesdramatically,formingachannelwith()electricalconductivityinthegasgap,andthegaswillloseitsinsulatingability.A

verylowB

veryhighCgeneralDuncertain第14题

TherelationshipcurvebetweengasbreakdownvoltageandPS(pressurevs.time)showsthatwiththechangeofPS,thebreakdownvoltagewillappear()A

maximalvalueB

minimalvalueC

averagevalue

Drandomvalue第15题Thedischargethatcanbemaintainedby()iscalledself-sustainingdischargeA

temperatureBlightirradiationCelectricfield

Dultravioletlight第16题Gasisnotanidealinsulator,however,whentheelectricfieldisweakandthereareveryfewchargedmasses,gasisstillagoodinsulator.第17题Electronsarelightinmassandsmallinsize,andthefreetravelbetweentwoadjacentcollisionswithothermassesismuchlargerthanthatofions,soitiseasytoaccumulateenoughenergyundertheelectricfield,andthencollidewithothermasses,whichisnoteasytooccurionizingcollision.第18题Themediumcanalsoundergophotoionizationundervisiblelightirradiation.第19题Townsendtheoryisusedtoexplainthebreakdownofgaseswithsmallairgapsatlowpressure第20题Whichofthefollowingphenomenaisnotconsideredinthestreamertheory?A

thermalionization

Bphotoionization

CelectricfielddistortionDtemperaturechange第21题Inwhichofthefollowingelectricfieldsiscoronadischargemostlikelytooccur?(

)A

uniformelectricfieldBslightlynonuniformelectricfieldCverynonuniformelectricfield第22题Thecoronavoltageofthenegativeplateofthepositiverodis()thanthatofthepositiveplateofthenegativerod

AlowBhighC

uncertain第23题Theformationconditionofstreameristheself-sustainingdischargeconditionofstreamertheory第24题Coronadischargeisnotaself-sustainingdischarge.第25题Thelongerthegap,themorefullythepilotprocessdevelops第26题Themoreuneventheelectricfieldisatthesamegapdistance,thehigherthebreakdownvoltageoftheairgap第27题Theelectricfield,theeasiertheimpuritiesintheliquidarrangedintoa“smallbridge”,thelowerthebreakdownvoltage

第28题Thebreakdownprocessoftheliquidmediumismorecomplex,moreinfluencingfactors,avarietyofaffectingfactorschangegreatly,thebreakdownvoltagedispersionislarg第29题Whenthepurityofoilishigh,improvingtheuniformityofelectricfieldcannoteffectivelyincreasethebreakdownvoltageofpowerfrequencyorDC.第30题Soliddielectricbreakdownincludeselectricbreakdown,thermalbreakdownandelectrochemicalbreakdown,andthesethreeformsareoftenexistingatthesametime.()第31题Thehigherthesurroundingtemperature,theworsetheheatdissipationconditions,thehigherthethermalbreakdownvoltage.()

第1题Whenconductinginsulationtest,thetemperatureofthetestobjectshallnotbelowerthan()degreecentigradeA+5

B0

C-5D-10第2题Wheninsulationtest,outdoortestshallbecarriedoutingoodweather,andtherelativehumidityoftheairisgenerallynothigherthan()%A70

B75

C80D85第3题Inordertofacilitatethefieldtestwork,thereareanumberofseparatetestrecordsofdifferenttestvoltagesofpowerequipment,inseparatetestdifficulties,canalsobeconnectedtogetherfortest,butthe()testvoltageshallbeusedintheconnectedequipmentA

thehighestB

thelowestCtheaveragevoltage第4题Whentheuseofhigherratedvoltageequipmenttostrengthentheinsulation,testvoltageshallbedeterminedinaccordancewiththeteststandardoftheratedvoltageof().A

equipmentBactualuseCgrid第5题Ingeneral,onlyaftertheinstallationofelectricalequipmenthasbeencompletedandcheckedfortestconditions,canthehandovertestbearranged.第6题Inordertofacilitatecomparisonoftestdataovertheyears,preventivetestsofthesameequipmentareusuallyarrangedinthesameseasonasfaraspossible.

第7题Contingencymeasuresshallbetakenforunqualifiedtestobjects,andtestobjectsthatfailthetestcanbetemporarilyputintooperation第8题Testpersonnelmustunderstandthetechnicalrequirementsofthetestobjectsandbefamiliarwiththerelevantprovisionsoftheteststandard第9题()shallberesponsibleforthesafetyofthesiteequipmentandpersonnel,andstaffmustfollowthecommandofthepersoninchargeofthework.AtheoperatorBthepersoninchargeoftheworkC

supervisionstaff第10题Highvoltagetestshall()AfillinthefirstkindofworkticketBfillinthesecondkindofworkticket

Cdonotfillintheworkticket第11题Thetestsiteshallbeequippedwithacoverbar,andthesign“()”shallbehungoutward.A

forbiddentoclosethegate,someoneworkB

stop,high-voltagedanger

Cworkhere第12题Themetalshellofthetestdeviceshallbe()

A

notgrounded

BgroundedbythearcextinguishingcoilC

reliablegrounding第13题Whencarryingoutoutdoortests,suchasinthecaseoflargewind,thunder,rain,snowandotherweather,high-voltagetestworkshallbecarriedoutcontinually第14题Ifdefectsorfaultsarefoundinequipmentandprotectiondevicesduringinspection,theyshallbereportedtotherelevantsuperiorsanddutyofficersinatimelymannerandbeimmediatelytroubleshot第15题High-voltagefusesshallnotcrosspavementsandstairs,etc.Thefencearoundthetestsitemustbeclosed,andwarningsignsandplacardsshallbehunginobviouspositions.

Examination第1题Forthemegohmmeteropencircuittest,thepointershallpointto()A0

B∞

Canyposition第2题Forthemegohmmetershort-circuittest,thepointershallpointto().A0B

∞Canyposition第3题AccordingtothePreventiveTestCodeforElectricPowerEquipmentrequirements,usuallyratedvoltageof1000Vorlessequipment,usethemegohmmeterwith().A1,000VB

2,500VC5,000V第4题AccordingtothePreventiveTestCodeforElectricPowerEquipmentrequirements,usuallyratedvoltageof1000Vormoreequipment,usethemegohmmeterwith().A1,000VB2,500VC5,000V第5题Beforetestingtheequipmentinoperation,itshallbeconfirmedthattheequipmenthasbeenpoweredoffandcanbefullydischargedwithoutgrounding.()第6题

Aftertheleakagecurrenttest,should()reducethevoltagetozero,andthencutoffthepowersupplyAquicklyBslowlyCstepbystep第7题Theleakagecurrenttestmicro-ammeterwiringhasthreepositions,whichwiringmethodispreferred?(

)Athehigh-voltagesideofthetestobject

Bthelow-voltagesideofthetestobject

C

thelow-voltagesideofthetesttransformer第8题DCwithstandvoltagetestisanon-destructivetest第9题

TheDCwithstandvoltagetestiscarriedoutonthebasisoftheleakagecurrenttest,whichcanfinddefectsthatcannotbedetectedbytheACwithstandvoltagetest.

第10题Accordingtotheregulationsontheequipmentinsulationpluspowerfrequencytestvoltage()doesnotoccurflashoverorbreakdownphenomenon,itisconsideredthattheequipmentinsulationisqualified.A30seconds

B

45seconds

C60seconds

D

90seconds第11题Duetotheexistenceofcapacitiveeffect,measurementifthevoltageatbothendsofthetestobjectaccordingtotheratioofconversion,maymakethevoltageonthetestobject()theexpectedtestvoltage.A

lowerthanB

higherthan

Cequalto第12题ACwithstandvoltagetestistheidentificationofelectricalequipmentinsulationstrengthofthemostrigorous,themosteffectiveandmostdirecttestmethod,itisadestructivetest.第13题Underthetestvoltage,itwillnotcausethecumulativeeffectwithintheinsulation.

第14题

ACwithstandvoltagetestregulatorshallbeabletomakethetesttransformerfromzerotothemaximumvaluewithuniformadjustment.

第15题DCresistancemeasurementtestisnotdirectlyrelatedtoinsulation,butthisisa()methodtofindconductordefectsinelectricalequipment.A

sensitive

Beffective

Cscientific第16题Thecurrentmeterpointerisnotalwaysadjustedtozero,butdeviatesgreatlytotheleftorright,indicatingthattheoriginalselectedmultiplierisnotsuitable.

第17题ThemeasurementofDCresistanceofelectricalequipmentisaveryimportantandessentialtestiteminthePreventiveTestCodeforElectricPowerEquipment.第18题

Ifthepointercannotstayatthezeropoint,youcanrotatetheflowdetectoradjustertocorrectthepointertothezeroposition.第19题Fortheoperatingpowerplant,substationgroundingnetwork,ifthereisinterferencecurrentflowingthroughtheground,doesithaveanyeffectonthemeasurementresults?AyesB

noC

uncertain第20题Groundingresistanceshallbecarriedoutindryweather,avoidimmediatelyafterrain,recordtheweatherconditionswhenmeasuring.第21题

Whenthereispaintorrustatthegroundingpointbeingmeasured,thegroundingresistanceshallberemovedbeforemeasurement.第22题Voltage,ammetermethodalsoknownasthethree-polemethod,whichissuitableforsmallareagroundingnetworkgroundingresistancetest第23题InsulationrodACwithstandvoltagetesttimeis()A1min

B2min

C

3minD5minExamination第1题Whengroundingtheratiotester()

Afirstconnecttothegroundterminal,thentotheinstrumentterminal

Bfirstconnecttotheinstrumentterminal,thentothegroundterminal

CBothAandB第2题Testsiteshallbeinstalledtocoverfenceorrail,hangingoutward()signage.

AForbiddentoClosetheGate,SomeoneWorking

BFromthisUpandDown

CWorkHere

D

Stop,High-VoltageDanger第3题Transformeroilcannotbeusedas().AliquiddielectricB

heatdissipation

C

ArcextinctionDConductor第4题

Thepurposeofmeasuringthetransformerratiois:()AtoensurethatthetransformerratioofwindingofeachtapisinthetechnicallypermissiblerangeB

tocheckthecorrectnessofnumberofturnsofthewindingC

todeterminewhetherthewindingofeachtapleadandtapswitchconnectioniscorrectDAlltheabovearetrue第5题Whenusingthedischargerod,thehumanbodyshallmaintainasufficientsafetydistancewithliveequipment,theoperator'shandgrippartshallnotcrossthegripparttomaintaintheeffectiveinsulationlength第6题Whenusingthedischargerod,thehumanbodyshallmaintainasufficientsafetydistancewithliveequipment,thegirls'strengthisnotenough,theoperatorcancrossthegrippartofthehandgripaslongastheoperatorwearsinsulatedgloves.第7题

Themetaltipofthedischargerodshallbeslowlyclosedtotheequipmenttobedischargedwhendischarging.第8题Transformercouplinggrouptestisusedtocheckwhetherthetransformercouplinggroupandtransformernameplatethesame.第9题

For10kVtransformer,intheDCresistancetestanalysisandjudgment,threephaseresistanceimbalanceormeasuredvalueandthedesignvalue(factorytestvalue)toomuchdifference,therearegenerallypossiblereasons:

AAfterthetransformeroverhaul,theboltsattheconnectionbetweentheconductingrodandtheinternalleadwiresinthebushingarenottightenedtightly,resultinginthecontactheatingphenomenonB

Poorleadandwindingweldingqualitycausingthelargecontactresistance,oroneorseveralstrandsofshunt-woundstructurewithmultiplewirearenotweldedon,causinginhighresistanceC

Themeasuredresistanceofthethreephaseswillbemuchlargerthanthenormalvalue(atthistime,twophasesdisconnectedlargerthanthenormalvaluefor1.5times,whilethedisconnectedphaseis3timesforthenormalvalue),itcanbedeterminedthatthetrianglewiringphaseisdisconnectedDAlltheabovearetrue第10题

Thevoltagelevelofthedischargingrodmustmeettherequirementsofthevoltageleveloftheequipmentbeingoperated,donottakearbitrarily.第11题Inordertopreventmoistureandproducealargeleakagecurrent,endangeringthesafetyoftheoperator,whenusingthedischargingrod,weshallwearinsulatedgloves.第12题Beforetheuseofthesafetyhelmet,checktheappearance,capshellshallbewithoutcracksordamageanddonothaveobviousdeformation.第13题WhenmeasuringthetransformerDCresistance,testervoltageleadisinthecurrentleadoutside,thiswillnotcausetoomuchdifferencebetweenthemeasuredvalueandthedesignvalue(factorytestvalue).第14题Intheelectricaltest,measuringtheDCresistanceofelectricalequipmentisgenerallyusedclamp-onammeter.第15题

Ifthethree-phasetransformerhasneutrallead,theresistanceofeachphasewindingshallbemeasured;Ifthethree-phasetransformerhasnoneutrallead,theinsulationresistancebetweenconductorsshallbemeasured第16题Inthevoltage

raisingofpuncturetestprocess,ifthecurrentvalueisfoundtoincreaserapidly,itshallimmediately()raisethevoltage.A

continue

B

stop

Cfast第17题WhenconducttheACpuncturetest,toohighavoltagewillmaketheinsulationdielectriclossincreases,heat,discharge

toacceleratethedevelopmentofinsulationdefects.第18题WhenconducttheACpuncturetest,afterallwiringiscompleted,

itcanbedirectlypressurizedwithout

check.第19题Whenconductthe

ACwithstandvoltage,we

shall

payattentiontoobservethevoltmeter,ifit

rises

tothespecifiedvoltagevalue,thenstopcontinuingtoraisethevoltage.第20题QS1bridgecontainsasetoflow-voltagepowersupplyandmortgagestandardcapacitor,whichcanmeasurethetestproductwithaelectriccapacityof30PF~100uf.第21题WhenusingQS1bridgeforreversewiringtesttanδ,itsworkingvoltageshall

notexceed10kV.第22题Whentheinsulationresistancemeterisforshort-circuittest,if

theresistancemeterisstillrotatingatlowspeed,

instantaneouslyshortwirethe

"L","E"terminal,thepointershall

indicate

A0B

Middle

C∞第23题Whenmeasuringtheinsulationresistanceofthetestproduct,thecondition

generallyshall

beintherelativehumidityoftheairthat

nothigherthanA

10%B30%C

50%D80%第24题Measuretheinsulationresistanceoftheprimarywindingandthesecondarywindingoftheelectromagneticvoltagetransformer.Eachnon-testedwinding,base

and

shellshall

begrounded

whenmeasuring.第25题Themetaltipofthedischargerodshallbeslowlyclosedtotheequipmenttobedischargedwhendischarging第26题Currenttransforme