機(jī)電專業(yè)英語(yǔ)第2版14Unit 14

Unit14Resistor,CapacitorandInductor電阻(diànzǔ)電容和電感精品資料Resistor,

CapacitorandInductor精品資料TranslationReadingMoreTranslatingskillsTextResistor，CapacitorandInductor精品資料

Ifabatteryisconnectedacrossaconductingmaterial，acertainamountofcurrentwillflowthroughthematerial.Thiscurrentisdependentonthevoltageofthebattery,onthe

dimensions

ofthesample,andonthe

conductivityofthematerialitself.1

The

oppositiontocurrentiscalledelectricalresistanceandisrepresentedbythelettersymbolR.Theunitofresistanceistheohm,atermthatisoftenexpressedbyusing?.Oneohmisdefinedasthatamountofresistancethatwilllimitthecurrentinaconductorisoneamperewhenthevoltageappliedtotheconductorisonevolt.Largeramountsofresistancearecommonlyexpressedinkiloohm

(K?)andinmegohm

(M?).

Resistors電阻假若將電池連接在導(dǎo)電材料上，一定數(shù)量的電流將流過(guò)此材料，流過(guò)材料的電流取決于電池的電壓、材料的截面積和材料自身的電阻率。對(duì)電流的阻力叫電阻，用字母符號(hào)R表示。電阻的單位是歐姆．通常用(chánɡyònɡ)表示。l歐姆的定義為：當(dāng)加到導(dǎo)體上的電壓為l伏特時(shí)，將導(dǎo)體中的電流限制在1安培所需要的電阻值。較大的電阻值常用(chánɡyònɡ)千歐(K?)和百萬(wàn)歐姆(M?)表示。精品資料

Theresistorsaremadefrom

carbon

mixtures,metal

films,orresistance

wireandhavetwoconnectingwiresattached.Variableresistors,withanadjustableslidingcontactarm,areoftenusedtocontrol

volume

onradiosandtelevisionsets.電阻可以由碳混合物、金屬薄膜或電阻絲制成，它有兩個(gè)連線接頭。常常用帶有滑動(dòng)(huádòng)臂的可變電阻器來(lái)控制收音機(jī)和電視機(jī)的音量。精品資料

Electricalenergycanbestoredinanelectricfield.Thedevicecapableofdoingthisiscalledacapacitorora

condenser.Capacitorsconsistoftwometalplatesthatareseparatedbyall

insulating

material.2

Ifabatteryisconnectedtobothplates,anelectricchargewillflowforashorttimeand

accumulate

oneachplate.Ifthebatteryis

disconnected，thecapacitor

retains

thechargeandthevoltageassociatedwithit.3Capacitors電容器電能可以儲(chǔ)存在電場(chǎng)中，能夠儲(chǔ)存電能的裝置叫電容器。電容器是由被絕緣材料分開(kāi)的兩個(gè)金屬板組成。如果(rúguǒ)電池被連接在兩個(gè)金屬板上，電荷將經(jīng)過(guò)很短的流動(dòng)而匯集在一個(gè)電極板上。假若斷開(kāi)電池，電容器將保持電荷以及與電荷相關(guān)的電壓。精品資料

Theabilityofacapacitortostoreelectricalenergyistermed

capacitance.

Thecapacitanceisdirectly

proportionaltothe

dielectric

constantofthematerialandtotheareaoftheplatesand

inversely

tothedistanceoftheplates.4Itismeasuredin

farads.Whenachangerofonevoltpersecondacrossitcausesthecurrentofoneamperetoflow,thecondenserissaidtohavethecapacitanceofonefarad.However,faradistoolargeaunittobeusedinradiocalculation,so

microfarad(10-6farads)andthe

picofarad

(10-12farads)aregenerallyused.電容器儲(chǔ)存電能的能力叫電容。電容器的電容量與介質(zhì)的介電常數(shù)及平板的面積成正比，與平板間的距離成反比，其大小用法拉表示。當(dāng)電容器兩端的電壓以每秒1伏的速率變化，產(chǎn)生的電流為1安培，就稱電容器的電容量為1法拉。在無(wú)線電方面(fāngmiàn)的計(jì)算中，法拉的單位太大，因此常用微法(法拉)和皮法(法拉)。精品資料

Inductorsconsistofaconductingwirewoundintotheformofa

coil.Whenacurrentpassesthroughthecoil,amagneticfieldissetuparounditthattendstoopposerapidchangesincurrent

intensity.5

Allcoilshave

inductance．

Inductor電感電感是由繞成線圈形狀的導(dǎo)線組成。當(dāng)電流(diànliú)通過(guò)線圈時(shí)，在線圈周圍將產(chǎn)生磁場(chǎng)，它將阻止電流(diànliú)的快速變化。一切線圈，都有電感。

精品資料

Acoilofmanyturnswillhavemoreinductancethanoneoffewturns.Alsoifacoilisplacedonaniron

core

itsinductancewillbegreaterthanitwaswithoutthemagneticcore.

Theunitofinduct-anceTheunitofinductanceisthe

henry.Acoilhasaninductanceofonehenryifan

induced

emf

ofonevoltisinducedinthecoilwhenthecurrentthroughitchangesattherateofoneampereparsecond.6Valuesofinductanceusedinradioequipmentvaryoverawiderange.匝數(shù)多的線圈比匝數(shù)少的線圈電感更大。而且，假若(jiǎruò)線圈中放一個(gè)鐵芯它的電感將比沒(méi)有鐵芯的線圈的電感更大。電感的單位是亨利。當(dāng)流過(guò)線圈的電流以每秒1安培的速度變化時(shí)，如果線圈中感應(yīng)出1伏特感應(yīng)電動(dòng)勢(shì)，那么，線圈的電感就是1亨利。用于無(wú)線電設(shè)備的電感值的變化范圍很大。精品資料

capacitor[k?'p?sit?]n.電容器capacitance[k?'p?sit?ns]n.電容；電流容量inductor[in'd?kt?]n.授職者；感應(yīng)器inductance[in'd?kt?ns]n.感應(yīng)系數(shù)；自感應(yīng)；電感dimension[di'men??n,dai-]n.維；尺寸；vt.標(biāo)出尺寸adj.規(guī)格的conductivity[,k?nd?k'tiviti]n.傳導(dǎo)性；導(dǎo)電性；傳導(dǎo)率opposition[,?p?'zi??n]n.反對(duì)；敵對(duì)；相反；反對(duì)派carbon['ka:b?n]n.碳；碳棒；復(fù)寫(xiě)紙adj.碳的；碳處理的film[film]n.膠卷；薄膜；輕煙；膜層vi.生薄膜；volume['v?lju:m]n.體積；卷；冊(cè)；音量(yīnliàng)；大量；adj.大量的精品資料wire['wai?]n.金屬絲；電線；電報(bào)vt.拍電報(bào)；給……裝電線condenser[k?n'dens?]n.冷凝器；壓縮器；聚合器；電容器proportional[pr?u'p?:??n?l]adj.成比例的；相稱的，n.比例項(xiàng)insulate['insjuleit]vt.隔離，使孤立；[物]使絕緣，使隔熱insulatingadj.絕緣的；隔熱的（insulate的ing形式）accumulate[?'kju:mjuleit]vi.累積；積聚vt.積攢disconnect[,disk?'nekt]vt.拆開(kāi)(chāikāi)，使分離vi.斷開(kāi)retain[ri'tein]vt.保持；雇；記住dielectric[,daii'lektrik]adj.非傳導(dǎo)性的；誘電性的n.電介質(zhì)；絕緣體inversely['inv?:sli]adv.倒轉(zhuǎn)地；相反地；反比例地精品資料farad['f?r?d]n.法拉（電容單位）microfarad[,maikr?u'f?r?d]n.微法拉（電容量的實(shí)用單位）picofarad['paik?u,f?r?d]n.微微法拉（百億分之一法拉）coil[k?il]vt.盤(pán)繞，把……卷成圈vi.成圈狀n.卷；線圈intensity[in'tens?ti]n.強(qiáng)烈；強(qiáng)度；亮度(liàngdù)；緊張；集中程度core[k?:]n.核心；果心；要點(diǎn)；磁心(ironcore鐵芯)induced[in'dju:st]adj.感應(yīng)的；引誘的（induce的過(guò)去分詞）henry['henri]n.亨(利)[電感單位，略作H]pl.henrys,henries精品資料variableresistor可變電阻器slidingcontact滑動(dòng)觸點(diǎn)dielectricconstant介電常數(shù)(jièdiànchánɡshù)，電容率magneticfield磁場(chǎng)emfabbr.n.電動(dòng)勢(shì)(ElectromotiveForce)精品資料1.capacitance[k?'p?sit?ns]n.電容；電流容量；機(jī)械容量1)relatedphrases：inputcapacitance輸入電容equivalentcapacitance等效(děnɡxiào)電容capacitancecoupling電容耦合capacitancerelay電容式繼電器shantcapacitance分流電容；并聯(lián)電容anodecapacitance陽(yáng)極電容howtheyareappliedinelectronicindustry.精品資料2）Features:Highvoltage,smallcollectoroutputcapacitance.特點(diǎn):耐壓高,集電極輸出電容小。3）Arethereanyprecautionswhenadjustingthecapacitancevalue?調(diào)整電容值時(shí)有哪些注意事項(xiàng)?4）Theformulaofcapacitanceandvoltagedependenceofpowerhasbeeneduced.推導(dǎo)(tuīdǎo)出了功率隨電容和電壓變化的計(jì)算公式。精品資料2．dimensionn.維；尺寸；容積vt.標(biāo)出尺寸adj.規(guī)格的1)relatedphrases：angulardimension角度標(biāo)注；角度大小(dàxiǎo)lineardimension線性尺寸verticaldimension垂直尺度f(wàn)itdimension配合尺寸underdimension尺寸過(guò)小dimensionscale標(biāo)注比例精品資料2）Lengthisonedimension,andwidthisanother.長(zhǎng)是一種度量，寬又是一種度量。3)Theproblemofthevehiclevelocitydetectionisresolvedbyonedimensionvideotracing.通過(guò)一維視頻跟蹤的方式，解決了車輛速度檢測(cè)的難題(nántí)。4)Thefinancialdimensiontomarkethigh-qualityproducts,qualityservicetowincustomers.維融以優(yōu)質(zhì)的產(chǎn)品占領(lǐng)市場(chǎng)，以優(yōu)質(zhì)的服務(wù)贏得了客戶。精品資料3.volumen.體積；卷；音量；大量；adj.大量的vt.把…收集成卷1)relatedphrases：volumelabel卷標(biāo)號(hào)boundvolume合訂本volumecontrol播放控制臺(tái)volumefraction體積分率；容積比criticalvolume臨界(línjiè)容積strokevolume沖程容積；心搏量精品資料2）Theprogressschedulecompiledonthebasisofvolumeproduction.根據(jù)批量產(chǎn)品生產(chǎn)預(yù)定時(shí)間表編制的進(jìn)度計(jì)劃；3）Largevolumeofdataweregathered.人們收集了大量的資料。4）Webuyinvolumeandcontractearlytogetthebestprices.大宗采購(gòu)和盡早(jìnzǎo)簽訂合同以獲得最低貨源價(jià)格。精品資料4．a(chǎn)ccumulate[?'kju:mjuleit]vi.累積；積聚vt.積攢1)relatedphrases：accumulateexperience獲取經(jīng)驗(yàn)(jīngyàn)accumulatepoints積分accumulatepick多重選擇accumulatefunds積累資金accumulatedose總劑量，累計(jì)劑量精品資料2)WhenweaccumulatemoreandmoresuchdifferencesbetweenChineseandEnglishconsciously,wewillthinkinEnglishwhenwespeakEnglish.當(dāng)我們有意識(shí)地積累了越來(lái)越多的類似的英漢差異之時(shí)，我們就開(kāi)始用英語(yǔ)思維來(lái)表達(dá)事物了。3）Overall,therefore,thecountrydidnotaccumulatesubstantialforeigncurrencyreserves.因此，總體來(lái)看，中國(guó)沒(méi)有積累很大的外匯儲(chǔ)備(wàihuìchǔbèi)。4）Accumulateandsummarizeallkindsofindexcompleted.Dothebasicandpreparationjoboffinancialbudget.積累總結(jié)各項(xiàng)指標(biāo)完成情況的資料，做好財(cái)務(wù)預(yù)算的基礎(chǔ)準(zhǔn)備工作。精品資料5．intensity[in'tens?ti]n.強(qiáng)烈(qiánɡliè)；強(qiáng)度；亮度；緊張；集中程度1)relatedphrases：fieldintensity磁場(chǎng)強(qiáng)度earthquakeintensity地震強(qiáng)度radiantintensity發(fā)光度,輻射率,輻射強(qiáng)度loadingintensity荷載強(qiáng)度intensityofmarketposition市場(chǎng)地位的集中程度精品資料2)Compact,highmagneticinductionintensityandlongcoilservicelife.結(jié)構(gòu)緊湊，磁感應(yīng)強(qiáng)度高，線圈使用壽命長(zhǎng)。3)Thisreducesthelaborintensity,reducepollution,conservewaterresources.這就降低了勞動(dòng)強(qiáng)度、減少(jiǎnshǎo)污染、節(jié)約水資源。4)Compact,highmagneticinductionintensityandlongcoilservicelife.結(jié)構(gòu)緊湊，磁感應(yīng)強(qiáng)度高，線圈使用壽命長(zhǎng)。精品資料6.induced[in‘dju:st]adj.感應(yīng)的；v.引誘；說(shuō)服（induce的過(guò)去分詞)1)relatedphrases：inducedcircuit感應(yīng)電路；inducedcurrent感生/應(yīng)電流；inducedradiation感應(yīng)(生)放射性；inducedfailure誘發(fā)故障；inducedoperation誘導(dǎo)(yòudǎo)運(yùn)算精品資料2）Nauseaanddizzinessinducedbymotion,asintravelbyaircraft,car,orship.暈船（車）：由運(yùn)動(dòng)引起的惡心和眩暈，如乘飛機(jī)、小汽車或輪船(lúnchuán)。3）Theroadtrafficaccidentsinducedbyfatiguedrivingwillleadtoseverepersonalcasualtyandpropertyloss.疲勞駕駛引發(fā)的道路交通事故導(dǎo)致了嚴(yán)重的人身傷亡和財(cái)產(chǎn)損失。精品資料7．ironcore：鐵芯magneticcore：磁芯core[k?:]n.果心,核心,要點(diǎn)vt.挖去(水果(shuǐguǒ)的)果心1)relatedphrases：cablecore電纜芯線；電纜心corediameter芯樣直徑；根徑corepin心型梢；中心銷corecompetence/competenc核心能力；關(guān)鍵才能精品資料2）Theearthhaveacoreandamantlearoundit.地球的中心是地核，地核的周圍是地幔。3）Teamspiritisthecoreofenterpriseculture.團(tuán)隊(duì)精神，是企業(yè)文化的核心。4）Themonopolypricingpoweristhecoremeaning.壟斷(lǒngduàn)最核心的意義就是定價(jià)權(quán)。5）Atthecoreofcompetitiveness,likehowtoattractnewcompetitiveness.在核心競(jìng)爭(zhēng)力不足的時(shí)候，就想怎么吸引新的競(jìng)爭(zhēng)力。精品資料1.Thiscurrentisdependentonthevoltageofthebattery,onthedimensionsofthesample，andontheconductivityofthematerialitself.流過(guò)材料的電流取決于電池的電壓(diànyā)、材料的截面積和材料自身的電阻率。句中bedependent(on)：“由……決定，取決于”，又如：1)Seatingloadandtightnessisdependentonbackpressure.閥座密封負(fù)載和緊密性與反壓力相關(guān)。精品資料2)Tourismisaresourceandtheenvironmentisheavilydependentontheindustry.旅游業(yè)是一個(gè)對(duì)資源和環(huán)境嚴(yán)重依賴的行業(yè)。3)Mayyoufindenoughinnerstrengthtodetermineyourownworthbyyourself,andnotbedependentonanother’sjudgmentsofyouraccomplishments.愿你能充分發(fā)掘自身潛能，以決定你的價(jià)值(jiàzhí)所在，不要讓別人的評(píng)判埋了你的成績(jī)。精品資料2.bedefinedas：“被定義為”，后接賓語(yǔ)，或“that”引導(dǎo)的賓語(yǔ)從句。如：1）Oneohmisdefinedasthatamountofresistancethatwilllimitthecurrentinaconductorisoneamperewhenthevoltageappliedtotheconductorisonevolt.l歐姆的定義為：當(dāng)加到導(dǎo)體上的電壓為l伏特時(shí)，將導(dǎo)體中的電流限制在1安培所需要的電阻值。句中第一個(gè)that作定語(yǔ)(dìngyǔ)，第二個(gè)that引導(dǎo)定語(yǔ)(dìngyǔ)從句，該從句本身包含了一個(gè)when引導(dǎo)的時(shí)時(shí)間狀語(yǔ)從句。精品資料2）Amoleculemaybedefinedasthesmallestparticleofmatterthatcanexistwithoutchangingitsnature.分子可以被定義為物質(zhì)在不改變其性質(zhì)的情況下而能存在的物質(zhì)的最小粒子。3)Motionmaybedefinedasacontinuouschangeofabodyinpositionwithrespecttosomeotherbodyorbodiesatrest.運(yùn)動(dòng)可定義為一個(gè)物體(wùtǐ)相對(duì)于另一個(gè)或幾個(gè)靜止物體(wùtǐ)在位置上的連續(xù)變化。精品資料3.Capacitorsconsistoftwometalplatesthatareseparatedbyallinsulatingmaterial.電容器是由被絕緣材料分開(kāi)的兩個(gè)金屬板組成。句中that引導(dǎo)定語(yǔ)從句，修飾twometalplates，consistof表示“由……組成”，又如：1）Auditrisksconsistofintrinsicrisk,controlriskandexaminationrisk.審計(jì)風(fēng)險(xiǎn)由固有風(fēng)險(xiǎn)、控制風(fēng)險(xiǎn)和檢查風(fēng)險(xiǎn)構(gòu)成。2）Modernwindfarmsconsistofturbinesthatgenerateelectricity.現(xiàn)代風(fēng)力(fēnglì)農(nóng)場(chǎng)由發(fā)電的渦輪機(jī)組成。精品資料4.Ifthebatteryisdisconnected，thecapacitorretainsthechargeandthevoltageassociatedwithit.如果斷開(kāi)電池，電容器將保持電荷(diànhè)以及與電荷(diànhè)相關(guān)的電壓。句中retain表示“保持；雇；記住”的意思。又如：1）Helpyourskinretainmoisture.幫助皮膚保持水分。2）Retainyouroriginalreceiptasproofofpurchase.請(qǐng)保留您的原始發(fā)票作為購(gòu)買(mǎi)證明。3）Moneyhastwofunctions,oneistoretainthevalueofwealth,theotherisanexchangevalueofthewealth.金錢(qián)有兩個(gè)職能，一個(gè)是保留財(cái)富價(jià)值，一個(gè)是交換財(cái)富價(jià)值。精品資料5.Thecapacitanceisdirectlyproportionaltothedielectricconstantofthematerialandtotheareaoftheplatesandinverselytothedistanceoftheplates.電容器的電容量與介質(zhì)的介電常數(shù)(jièdiànchánɡshù)及平板的面積成正比,與平板間的距離成反比。a）bedirectlyproportionalto：“與……成正比”b）beinverselyproportionalto：“與……成反比”又如：1)Theresistanceofathinfilm/coatingisdirectlyproportionaltotheresistivity,andinverselyproportionaltothethickness.薄膜鍍膜的電阻與該鍍鏌的電阻系數(shù)成正比,與厚度成反比.精品資料2)Themagnitudeoftheforceisfoundtobeinverselyproportionaltothedistancebetweentheconductors.人們發(fā)現(xiàn)力的大小與施力者之間的距離成反比。6.Whenacurrentpassesthroughthecoil，amagneticfieldissetuparounditthattendstoopposerapidchangesincurrentintensity．當(dāng)電流通過(guò)線圈時(shí)，在線圈周圍將產(chǎn)生磁場(chǎng)，它將對(duì)抗電流的快速變化(biànhuà)。句中that引導(dǎo)定語(yǔ)從句，修飾amagneticfield，it指代thecoil。opposevt..vi.表示“反對(duì)；對(duì)抗，抗?fàn)帯保秩纾壕焚Y料1）Smallbanksandsomestateofficialsstronglyopposetheplan.小銀行以及某些(mǒuxiē)州的官員強(qiáng)烈反對(duì)該方案。2）Weopposeallformsofhegemonismandpowerpolitics.反對(duì)各種形式的霸權(quán)主義和強(qiáng)權(quán)政治。精品資料7.Alsoifacoilisplacedonanironcoreitsinductancewillbegreaterthanitwaswithoutthemagneticcore.而且，如果線圈中放一個(gè)鐵芯，它的電感將比沒(méi)有(méiyǒu)鐵芯的線圈的電感大。句中than引導(dǎo)一個(gè)比較狀語(yǔ)從句。inductance[in‘d?kt?ns]n.“感應(yīng)系數(shù)；自感應(yīng)；電感”，又如：1）DCvoltageisdeterminedbyACvoltage,inductanceontheACside,andload.直流側(cè)直流電壓是由交流電壓、電感及負(fù)載決定的。精品資料2）TheeffectsofinductanceandcapacitancemakeitnecessarytocarefullydesignallACtransmissionsystems.電感和電容的影響，使人們必須精心地設(shè)計(jì)所有的交流輸電系統(tǒng)。8.Acoilhasaninductanceofonehenryifaninducedemfofonevoltisinducedinthecoilwhenthecurrentthroughitchangesattherateofoneamperepersecond.當(dāng)流過(guò)線圈的電流以每秒1安培的速度變化時(shí)，如果線圈中感應(yīng)出1伏特感應(yīng)電動(dòng)勢(shì)，那么，線圈的電感就是1亨利。attherateof“以……的速度/速率(sùlǜ)/比率/變化率/頻率”又如：精品資料1）Incomefrompropertytransactionsshallbefiledandtaxedattherateof35%.財(cái)產(chǎn)交易所得按35%扣繳率申報(bào)(shēnbào)納稅。 2）Profitsfromoccasionaltradeshallbefiledandtaxedattherateof30%.一時(shí)貿(mào)易的盈余按30%扣繳率申報(bào)(shēnbào)納稅。精品資料I.Answerthefollowingquestionsaccordingtothetext.

1.Whatiscalledaresistor?Whatistheunitofresistance?

2.Whatistheusageofvariableresistors?Theresistorsaremadefromcarbonmixtures,metalfilms,orresistancewireandhavetwoconnectingwiresattached.The

oppositiontocurrentiscalledelectricalresistance.Variableresistors,withanadjustableslidingcontactarm,areoftenusedtocontrolvolumeonradiosandtelevisionsets.keykey精品資料3.Whatiscalledacondenser?Whichelementsdocondensersconsistof?4.Howtodefineonefaradofthecapacitance?

Thedevicecapableofdoingthisiscalledacapacitororacondenser.Capacitorsconsistoftwometalplatesthatareseparatedbyallinsulatingmaterial.Whenachangerofonevoltpersecondacrossitcausesthecurrentofoneamperetoflow,thecondenserissaidtohavethecapacitanceofonefarad.keykey精品資料5.Whatareinductorsmadeupof?Howtodefineonehenryofaninductance?

Inductorsconsistofaconductingwirewoundintotheformofacoil.Acoilhasaninductanceofonehenryifaninducedemf

ofonevoltisinducedinthecoilwhenthecurrentthroughitchangesatthe

rateofoneampereparsecond.key精品資料II．Fillinthemissingwordsaccordingtothetext．

1.Thiscurrentdependsonthevoltageofthebattery,onthe____ofthesample,andonthe_________ofthematerialitself.A_____isadevicedesignedtohavecapacitance.3.Ohmisusedasaunitof__________.dimensionsconductivitycapacitorresistancekeykeykey精品資料4.Thelargeristheemf,themore___thecapacitorstores．5.Whenachangerofonevoltpersecondacrossitcausesthecurrentofoneamperetoflow,the___issaidtohavethecapacitanceofone_____.6.The___aremadefromcarbonmixtures，metalfilms，orresistancewireandhavetwo______wiresattached.capacitancecondenserfaradresistorsconnectingkeykeykey精品資料1.可變電阻器常用來(lái)控制(kòngzhì)收音機(jī)和電視機(jī)的音量。

2.電容器存儲(chǔ)電能的能力叫電容。Unit14Resistor,CapacitorandInductorVariableresistorsareoftenusedtocontrolvolumeonradiosandtelevisionsets.Theabilityofacapacitortostoreelectricalenergyistermedcapacitance.

III．TranslatethefollowingsentencesintoEnglish．keykey精品資料3.任何(rènhé)電感都是由線圈組成，線圈的匝數(shù)越多，電感越大。4.電容器的電容量與介質(zhì)的介電常數(shù)及平板的面積成正比,與平板間的距離成反比。Inductorsconsistofaconductingwirewoundintotheformofacoil.Acoilofmanyturnswillhavemoreinductancethanoneoffewturns.Thecapacitanceisdirectlyproportionaltothedielectricconstantofthematerialandtotheareaoftheplatesandinverselytothedistanceoftheplates.keykey精品資料And引導(dǎo)的句型的譯法And作連詞，用來(lái)連接詞、短語(yǔ)和句子，其基本意義相當(dāng)于漢語(yǔ)的“和”、“與”、“并且”。但在實(shí)際翻譯的過(guò)程中，特別是在連接兩個(gè)句子時(shí)，它的譯法很多，表達(dá)的意義可能相差甚遠(yuǎn)。如果不考慮and前后成分之間的邏輯關(guān)系，只用幾種基本譯法生硬套用，難免造成理解上的失誤，甚至把整個(gè)句子意思搞錯(cuò)。l.And表示(biǎoshì)原因，例如：Laseriswidelyusedfordevelopingmanynewkindsofweapons,anditpenetratesalmosteverything.激光廣泛用于制造各種新式武器，因?yàn)闉樗拇┩噶軓?qiáng)。精品資料2.And表示因果，譬如：1）Butsinceadigitalsignalismadeupofastringofsimplepulses,noisestandsoutandeasilyremoved.但由于(yóuyú)數(shù)字信號(hào)由一組簡(jiǎn)單脈沖組成，雜音明顯，容易發(fā)現(xiàn)，因而容易排除。2）Inl945anewtypeofaeroplaneenginewasinvented,itwasmuchlighterandpowerfulthanearlierengines,andenabledwarplanestoflyfasterandhigherthanever.1945年發(fā)明了一種新型的飛機(jī)發(fā)動(dòng)機(jī)。它比早期發(fā)動(dòng)機(jī)要輕的多，功率也要大得多，因此采用這種發(fā)動(dòng)機(jī)的軍用飛機(jī)比以往任何時(shí)候都飛得更快、更高。精品資料3.And表示目的，例如：Itwaslatershownthattheresultsofthisworkwerebynomeanstheultimate，andfurtherworkhasbeenputinhandandtoprovideclosercontrolandmoreconsistentoperationinthisarea.后來(lái)發(fā)現(xiàn)，這項(xiàng)研究工作的結(jié)果絕非已作定論，而進(jìn)一步的研究工作已開(kāi)始，以便在這方面提供較嚴(yán)密的控制和較穩(wěn)定的操作。4.And表示承接，譬如：Inmanyways,computerismoresuperiorthanhumanbrain,andhumancanruleit.在許多方面計(jì)算機(jī)超過(guò)人腦，而人卻可以控制它。5.And表示對(duì)照，例如：例:Motionisabsolute,andstagnationisrelative.運(yùn)動(dòng)(yùndòng)是絕對(duì)的，而靜止是相對(duì)的。精品資料6.And表示遞進(jìn)，譬如：例:Theelectronicbraincalculatesathousandtimesquicker,andmoreaccuratelythanispossibleforthehumanbeing.電腦的運(yùn)算(yùnsuàn)速度比人所能達(dá)到的要快1000倍，甚至更加準(zhǔn)確。7.And表示轉(zhuǎn)折，例如：例:Therewillalwaysbesomethingsthatarewrong,andthatisnothingtobeafraidof.錯(cuò)誤的東西在所難免，但并不可怕。精品資料8.And表示條件，譬如：Evenifaprogrammerhadendlesspatience,knowledgeandforesight,storingeveryrelevantdetailinacomputer,themachine’sinformationwouldbeuseless,andtheprogrammerknewlittlehowtoinstructitinwhathumanbeingsrefertoascommonsensereasoning.即使一個(gè)編程員很有耐心、知識(shí)和遠(yuǎn)見(jiàn)，把每一個(gè)有關(guān)細(xì)節(jié)都存入計(jì)算機(jī)，如果他不懂得按人類常識(shí)推理去對(duì)計(jì)算機(jī)下達(dá)指令，機(jī)器里的信息也還是沒(méi)有用途的。9.And表示結(jié)果(jiēguǒ)，例如：Operatorsfoundthatthewaterlevelwastoolowsotheyturnedontwoadditionalmaincoolantpumps,andtoomuchcoldwaterflowingintothesystemcausedthesteamtocondense,furtherdestabilizingthereactor.操作人員發(fā)現(xiàn)冷卻水的水位過(guò)低，就啟動(dòng)了另外兩臺(tái)主冷卻泵，結(jié)果(jiēguǒ)過(guò)量的冷卻水進(jìn)入系統(tǒng)使蒸氣冷凝，反應(yīng)堆因而更不穩(wěn)定。精品資料TestingandMeasuringInstrumentsAnalogMultimeter

DigitalMultimeter

Bench-typeDigitalMultimeter

DigitalStorageOscilloscope精品資料TestingandMeasuringInstruments

Onceaparticularcomponentissuspectedofbeingfaulty,individualtestsmustbethenperformed.Andthetestingandmeasuringinstrumentsoftentobeusedareasfollow:MultimeterAmultimeterissometimescalledavolt-ohm—milliammeter.Multimetershavingonlyvoltandohmrangesarealsocalledvolt-ohmmeters.Therearetwomainkindsofmultimeters.Theyaremechanicalhandymultimetersanddigitalones.It’sbetterforlearnerstousehandytypes,becauseit’shelpfulforthemtobefamiliarwithsomeelectronicprinciples.

測(cè)試儀器一旦懷疑某個(gè)(mǒuɡè)元件出故障，就得單獨(dú)做些測(cè)試。常用的測(cè)試與測(cè)量?jī)x器如下：萬(wàn)用表萬(wàn)用表有時(shí)候被稱為伏特-歐姆-毫安表。只具有電壓(伏特)和電阻檔(歐姆)的萬(wàn)用表也叫伏歐表。萬(wàn)用表主要有兩種：機(jī)械指針式萬(wàn)用表和數(shù)字式萬(wàn)用表。初學(xué)者最好使用指針式，因?yàn)橹羔樖饺f(wàn)用表有助于他們熟悉一些電子原理。精品資料

Usingamultimeter，youshouldfirstplaceitflatonatableandnoteifthemeterpointerindicatesexactly0attheextremeleftendoftheblackscale.[1]Ifitdoesn’tread0,turnthescrewonthemetermovementslowlyuntiltheproper0readingisrealized.[2]Andthenconnecttest-1eadtotheother．SettheRANGEswitchtotheproperitemandrange．Insertthetest-leadplugsintothecorrectpairofjacks，cliporholdthetestprobesontheterminalsofthepartbeingchecked，andreadthemeter．使用萬(wàn)用表時(shí)，首先你要將萬(wàn)用表平放在桌子上，檢查表針是否指向表盤(pán)最左端底部黑色分度的零位。如沒(méi)指到零位(如有偏離)，可慢慢轉(zhuǎn)動(dòng)萬(wàn)用表上的螺釘(調(diào)整(tiáozhěng)旋鈕)直到(指針)歸零。然后將測(cè)試引線連接起來(lái)。將“量程”旋鈕調(diào)至適當(dāng)?shù)捻?xiàng)目和量程上。將表筆插到正確的插孔內(nèi)，使表筆夾緊被檢測(cè)部件的末端，然后再讀出表上的讀數(shù)。精品資料

Withamultimeter,wecanmeasurecurrent,voltage,resistance,etc.Andwecanalsotroubleshootappliances,testfuses,measurevoltageatawalloutlet,checkthewiresfromyourroofantenna,findoutwhetherawallswitchisbroken,andperformdozensofotherhouseholdjobs.[3]Introubleshooting,voltagecanbemeasuredwhilethesetison,andresistancecanbemeasuredwhilethesetisoff.Yougetcluestothelocationofthetroublebycomparingyourmultimeterreadingswiththenormalvaluesgiveninservicemanuals.萬(wàn)用表可以用來(lái)(yònɡlái)測(cè)量電流、電壓、電阻等，也可以檢測(cè)各種裝置的電器故障，比如：檢測(cè)熔絲，測(cè)量墻上插座的電壓值，檢測(cè)房頂上的天線，查明墻上的開(kāi)關(guān)是否有了毛病，并完成許多其他，家用電器的檢修工作。檢測(cè)故障時(shí)，在被檢測(cè)設(shè)備通電的情況下，可以測(cè)量電壓而在測(cè)量電阻時(shí)卻要切斷被檢測(cè)設(shè)備的電源。將萬(wàn)用表上讀數(shù)值與使用手冊(cè)說(shuō)明上所標(biāo)定的額定數(shù)值對(duì)比一下，你就可以得到故障所在位置的線索。精品資料

OscilloscopeOscilloscopeisadisplayinstrument.Withityoucanstudythewave-formofanelectricsignal,suchasthewave-formofalternatingcurrentandvoltage.Youcanmeasurevoltage,current,power,andfrequencyaswell；infact,almostanyquantitythatinvolvesamplitudeandwaveform.示波器示波器是一種顯示儀器。你可以用它來(lái)研究電信號(hào)(例如交流電流和電壓)的波形。它也可用來(lái)測(cè)量電壓、電流、功率和頻率；實(shí)際上，它幾乎可以測(cè)量涉及(shèjí)到振幅和波形的任何一種量。精品資料

Theheartoftheoscilloscopeisthecathode-raytube(CRT).Thisconsistsofthebase,neck(anelectrongunisincluded),bulbandtheface-plate(screen).Theelectrongunconsistsofacathode,acontrolgrid,ananodeandtwosetsofdeflectionplates.Whenthecathodeisheated,itemitselectrons,whichformelectronbeam.Theelectronbeamsweepsrapidlyfromlefttorightacrossthescreenofacathode-raytube.However,recentlymostofthecathode-raytubesusedinoscilloscopeshavebeenreplacedbyLCDs(LiquidCrystalDisplays),whichgreatlydecreasetheweightandsizeoftheinstrument.示波器的心臟是陰極射線管(CRT)。它由管座、管頸(電子槍在內(nèi))、燈泡和面板(顯示屏)構(gòu)成。而電子槍由陰極、控制柵、陽(yáng)極和兩套偏轉(zhuǎn)板構(gòu)成。陰極受熱時(shí)發(fā)射電子，形成電子束。電子束快速?gòu)淖笾劣覓哌^(guò)陰極射線管的熒光屏。然而，近來(lái)大多數(shù)用于示波器的陰極射線管已經(jīng)(yǐjing)由LCDs(液晶顯示器)取代，液晶顯示器大大地減輕了儀器的重量、縮小了儀器的體積。精品資料multimeter[ml'timit?]n.[電]萬(wàn)用表milliammeter[,mili'?mit?]n.[電]毫安計(jì)pointer['pint?]n.指針；暗示；scale[skeil]n.刻度；比例；天平vi.攀登；衡量vt.測(cè)量；依比例決screw[skru:]vt.vi.轉(zhuǎn)動(dòng)；旋，擰；壓榨；強(qiáng)迫n.螺絲釘；吝嗇鬼insert[in's?:t,'ins?:t]vt.插入；嵌入；插入物lead[li:d]n.鉛；導(dǎo)線；引線vt.vi.導(dǎo)致；領(lǐng)導(dǎo)adj.帶頭的；最重要的plug[plɡ]n.栓；插頭；塞子vi.塞?。挥貌孱^將與電源接通jack[d??k]n.千斤頂；插座；插孔vt.提醒；用千斤頂頂起某物(mǒuwù)clip[klip]vt.修剪；夾牢；痛打vi.修剪n.夾子；修剪；回形針精品資料troubleshoot['trblu:t]vt.檢修，排除故障vi.充當(dāng)故障檢修員appliance[?'plai?ns]n.器具；器械；裝置設(shè)備；應(yīng)用(yìngyòng)fuse[fju:z]vi.熔化，熔融；融合vt.使熔化n.保險(xiǎn)絲；導(dǎo)火線；熔絲oscilloscope['sil?usk?up,?-]n.[電子]示波器；示波鏡cathode['k?θ?ud]n.陰極grid[ɡrid]n.[計(jì)]網(wǎng)格；格子，柵格；輸電網(wǎng)anode['?n?ud]n.[電]陽(yáng)極，正極deflection[di'flek?n]n.偏向；偏差；撓曲crystal[‘krist?l]n.水晶；晶體adj.水晶的；透明的，清澈的精品資料handymultimeter指針式萬(wàn)用表cathode-raytube(CRT)陰極射線管electrongun電子槍controlgrid控制(kòngzhì)柵(極)electronbeam電子束liquidcrystaldisplay(LCD)液晶顯示器精品資料

I．Choosethebestanswertocompletethefollowingstatements.

1.Accordingtothetext，_____isthemostcommontoolinrepairingwork．

A．oscilloscopeB．multimeterC．screwD．electrongun2．Themultimetermustbeputhorizontallyandthepointermustpointto_____A．theleftB