igcse-物理大纲

1、igcse-物理大纲1. GeneralPhysics普通物理1.1 Lengthandtime长度和时间1. Useanddescribetheuseofrulesandmeasuringcylinderstodeterminealengthoravolume.使用并且描述如何用尺子和量筒测量长度和体积。2. Useanddescribetheuseofclocksanddevicesformeasuringanintervaloftime.使用并且描述如何用钟表和一些仪器测量时间间隔。3. Useanddescribetheuseofamechanicalmethodforthemeasu

2、rementofasmalldistance.1使用并描述利用机械的方法测量短距离。4. Measureanddescribehowtomeasureashortintervaloftime(includingtheperiodofapendulum).测量和描述怎样测量一个短时间间隔(包括单摆的周期)。1.2 Speed,velocityandacceleration速率，速度，力口速度1. Definespeedandcalculatespeedfromtotaldistance/totaltime.定义速率和计算：速率=总路程/总时间2. Plotandinterpretaspeed/t

3、imegraphoradistance/timegraph.画和解释速率/时间图像或者路程/时间图像3. Recognizefromtheshapeofaspeed/timegraphwhenabodyis(a)atrest,(b)movingwithconstantspeed,or(c)movingwithchangingspeed.从速率/时间图像中辨认出：(a)静止，(b)匀速运动和(c)变速运动。4. Calculatetheareaunderaspeed/timegraphtodeterminethedistancetraveledformotionwithconstantaccel

4、eration.计算速率/时间图像中的面积得出匀加速运动的路程。5. Demonstratesomeunderstandingthataccelerationisrelatedtochangingspeed.解释加速度和速度的改变量之间的联系。6. StatethattheaccelerationoffreefallforabodyneartotheEarthisconstant.说明地球表面附近的物体自由降落的加速度是衡定的。7. Distinguishbetweenspeedandvelocity.区分速率和速度。8. Recognizelinearmotionforwhichtheacc

5、elerationisconstantandcalculatetheacceleration.认识匀加速的运动并且计算加速度。9. Recognizemotionforwhichtheaccelerationisnotconstant.认识非匀加速运动。10. Describequalitativelythemotionofbodiesfallinginauniformgravitationalfieldwithandwithoutairresistance(includingreferencetoterminalvelocity).定性的描述计和不计空气阻力物体在均匀重力场中下落的运动(包括

6、设计到末速度。1.3 Massandweight质量和重量1. Showfamiliaritywiththeideaofthemassofabody.熟练掌握一个物体的质量的概念。2. Statethatweightisaforce.陈述重量是一种力。3. Demonstrateunderstandingthatweights(andhencemasses)maybecomparedusingabalance.阐明重量(因此质量)可以用天平来比较。4. Demonstrateanunderstandingthatmassisapropertywhichresistschangeinmotion

7、.阐明质量是物体阻碍加速度的一种性质5. Describe,andusetheconceptof,weightastheeffectofagravitationalfieldonamass.描述和利用重力是重力场作用在物体上的效果的概念。1.4 Density密度1. Describeanexperimenttodeterminethedensityofaliquidandofaregularlyshapedsolidandmakethenecessarycalculation.描述一个测量液体或者规则形状的固体的密度的实验并做必要的计算。2. Describethedetermination

8、ofthedensityofanirregularlyshapedsolidbythemethodofdisplacementandmakethenecessarycalculation.描述通过替代法测量一个不规则形状的固体的密度并做必要的计算。1.5 Force力Effectsofforces力的作用效果1. Statethataforcemayproduceachangeinsizeandshapeofabody.说明一个力可以改变一个物体的大小和形状。2. Plotextension/loadgraphsanddescribetheassociatedexperimentalproce

9、dure.画伸长量/力的图像并描述这个相关实验过程。3. Describethewaysinwhichaforcemaychangethemotionofabody.描述力可以怎样改变一个物体的运动。4. Findtheresultantoftwoormoreforcesactingalongthesameline.求共线的两个或多个力的合力。10. Interpretextension/loadgraphs.解释伸长量/负荷的图象。11. StateHookeLawandrecallandusetheexpressionF=kx.说明胡克定律并记住使用F=kx。12. Recognizeth

10、esignificanceofthetermlimitofproportionalityforanextension/loadgraph.从伸长量/负荷图像中辨认出正比例限度。13. Recallandusetherelationbetweenforce,massandacceleration(includingthedirection).记住和应用力，质量和加速度之间的关系。(F=ma)。14. Describe,qualitatively,motioninacurvedpathduetoaperpendicularforce(F=mv2/risnotrequired).定性的描述物体在一个

11、垂直力的作用下沿曲线运动。(b) Turningeffect转动效果5. Describethemomentofaforceasameasureofitsturningeffectandgiveeverydayexamples.描述力矩是力的转动效果量度并且取例子。6. Describe,qualitatively,thebalancingofabeamaboutapivot.定性的描述一个杆关于支点的平衡。15. Performanddescribeanexperiment(involvingverticalforces)toverifythatthereisnonetmomentonabo

12、dyinequilibrium.演示和描述一个实验证明物体在合力矩为零时会保持平衡。16. Applytheideaofopposingmomentstosimplesystemsinequilibrium.应用反向的力矩简化一个系统的平衡。(c) Conditionsforequilibrium平衡的条件7. Statethat,whenthereisnoresultantforceandnoresultantturningeffect,asystemisinequilibrium.描述当合力为零并且合力矩为零时，系统保持平衡。(d) Centreofmass质心8. Performandd

13、escribeanexperimenttodeterminethepositionofthecentreofmassofaplanelamina.演示和描述一个在几何平面内找出物体质心的实验。9. Describequalitativelytheeffectofthepositionofthecentreofmassonthestabilityofsimpleobjects.定性的描述质心的位置对物体稳定的影响。(e) Scalarsandvectors标量和矢量17. Demonstrateanunderstandingofthedifferencebetweenscalarsandvect

14、orsandgivecommonexamples.阐明和理解标量和矢量之间的区别并且提出常见的例子。18. Addvectorsbygraphicalrepresentationtodeterminearesultant.通过图像表不求两个矢量的和。19. Determinegraphicallyaresultantoftwovectors.通过画图求两个矢量的和1.6Energy,workandpower能量，功和功率(a) Energy能量1. Demonstrateanunderstandingthatanobjectmayhaveenergyduetoitsmotionoritspos

15、ition,andthatenergymaybetransferredandstored.描述和理解一个物体由于运动和位置产生的能量，这个能量能够被转换和储存。2. Giveexamplesofenergyindifferentforms,includingkinetic,gravitational,chemical,strain,nuclear,internal,electrical,lightandsound.给一些不同形式的能量的例子，包括动能，势能，化学能，弹性势能，核能，内能，电能，光能和声能，3. Giveexamplesoftheconversionofenergyfromone

16、formtoanotherandofitstransferfromonplacetoanother.给一些从一种形式的能量转换为另一种形式的能量，从一个地方传播到另一个地方。4. Applytheprincipleofenergyconservationtosimpleexamples应用能量守恒的简单的例子。8. Recallandusetheexpressionsk.e.=?mv2andp.e.=mgh记住和应用表达式K.e=1/2mv和p.e=mgh(b) Energyresources能源5. Describehowelectricityorotherusefulformsofener

17、gymaybeobtainedfrom(i) chemicalenergystoredinfuel(ii) water,includingtheenergystoredinwaves,intides,andinwaterbehindhydroelectricdams(iii) geothermalresources(iv) nuclearfission(v) heatandlightfromtheSun描述电能和其它有用的能量形式怎样从下列能源获得的：(i)储存在然连中的化学能(ii)水包括储存在波和潮汐中的能量和水力电气水坝后面的水里面的重力势能(iii)地热能(iv)核裂变(v)来自太阳的

18、热和光能9. ShowanunderstandingthatenergyisreleasedbynuclearfusionintheSun.描述和理解太阳的核裂变释放能量10. Showaqualitativeunderstandingofefficiency定性的理解效率(c) Work功4-relate,withoutcalculation,workdonetothemagnitudeofaforceandthedistancemoved不通过计算找出做功与力的大小和移动的路程之间的关系5-describeenergychangesintermsofworkdone描述能量的改变就是做功6

19、-recallanduseZW=Fd=AE记住和应用(d) Power功率1-relate,withoutcalculation,powertoworkdoneandtimetaken,usingappropriateexamples不用计算用合适的例子找出功率与做功和时间的关系2-recallandusetheequationP=E/tinsimplesystems记住和应用在一个简单的系统P=E/t1.7Pressure压强1-relate,withoutcalculation,pressuretoforceandarea,usingappropriateexamples不通过计算，通过合

20、适的例子得出压强，力和面积之间的联系2-describethesimplemercurybarometeranditsuseinmeasuringatmosphericpressure描述简单的水银气压计和用它来测量大气压强3-relate,withoutcalculation,thepressurebeneathaliquidsurfacetodepthandtodensity,usingappropriateexamples不通过计算通过合适的例子得出液体表面下的压强，升读和密度之间的关系4-useanddescribetheuseofamanometer描述压力计的应用5recallan

21、dusetheequationp=F/A记住，会用等式P=F/A6-recallandusetheequationp=hpg记住会用等式p=pgh2. ThermalPhysics热学物理2.1 Simplekineticmolecularmodelofmatter物质简单分子动能模型(a) Statesofmatter物质的状态1-statethedistinguishingpropertiesofsolids,liquidsandgases描述固体，液体，气体性质的区别(b) Molecularmodel分子模型1-describequalitativelythemolecularstru

22、ctureofsolids,liquidsandgases定性的描述固体，液体，气体的分子结构2-interpretthetemperatureofagasintermsofthemotionofitsmolecules以分子运动来描述气体的温度3-describequalitativelythepressureofagasintermsofthemotionofitsmolecules以分子运动来定性的描述气体的压强。4-describequalitativelytheeffectofachangeoftemperatureonthepressureofagasatconstantvolum

23、e定性的描述体积不变时温度的变化对压强的影响。5-showanunderstandingoftherandommotionofparticlesinasuspensionasevidenceforthekineticmolecularmodelofmatter解释和理解粒子的随机运动是分子动力学模型的一个实例6-describethismotion(sometimesknownasBrownianmotion)intermsofrandommolecularbombardment用分子的随机轰炸来描述一种运动(布朗运动)7-relatethepropertiesofsolids,liquids

24、andgasestotheforcesanddistancesbetweenmoleculesandtothemotionofthemolecules联系固体，液体，气体的性质与分子间力，分子间距离和分子的运动8-showanappreciationthatmassiveparticlesmaybemovedbylight,fastmovingmolecules展示一定质量的粒子被光照后移动，并工移动加快。(c) Evaporation蒸发1-describeevaporationintermsoftheescapeofmore-energeticmoleculesfromthesurface

25、ofaliquid以高能量的分子从液体表面逃离的方式描述蒸发。2-relateevaporationandtheconsequentcooling联系蒸发和冷却结果3-demonstrateanunderstandingofhowtemperature,surfaceareaandoverasurfaceinfluenceevaporation描述理解温度，表面积和表面的气流对蒸发的影响。(d) Pressurechanges改变压强1-relatethechangeinvolumeofagastochangeinpressureappliedtothegasatconstanttempera

26、ture联系温度不变时，体积的改变引起压强的改变。2-recallandusetheequationpV=constantatconstanttemperature记住和应用当温度不变时等式，PV=常数2.2 Thermalproperties热性质(a) Thermalexpansionofsolids,liquidsandgases固体，液体和气体的热膨胀。1-describequalitativelythethermalexpansionofsolids,liquidsandgases定性的描述固体，液体和气体的热膨胀。2-identifyandexplainsomeoftheevery

27、dayapplicationsandconsequencesofthermalexpansion描述和解释一些生活中热膨胀的实例3-describequalitativelytheeffectofachangeoftemperatureonthevolumeofagasatconstantpressuremention定性的描述提到的压强一定时，温度对气体的影响。4-showanappreciationoftherelativeorderofmagnitudeoftheexpansionofsolids,liquidsandgases说明并展现固体、液体、气体之间膨胀的关系(b) Measur

28、ementofTemperature温度的测量1-appreciatehowaphysicalpropertywhichvarieswithtemperaturemaybeusedforthemeasurementoftemperatureandstateexamplesofsuchproperties赏识一下变化温度的物理性质被用来测量温度并描述一个类似的例子2-recogizetheneedforandidentifyfixedPoints识别和辨认所需要的固定点3-describethestructureandactionofliquidinglassthermometers描述一个液体

29、温度计的结构和作用4-demonstrateunderstandingofsensitivity,rangeandlinearity说明和理解灵敏度，变化范围和线性5-describethestructureofathermocoupleandshowunderstandingofitsuseformeasuringhightemperaturesandthosewhichvaryrapidly描述热偶的结构和理解用它来测量迅速变化的高温(c) Thermalcapacity热容量1-relateariseintemperatureofabodytoanincreaseininternalen

30、ergy描述一个物体的温度升高内能增加。2-showanunderstandingofthetermthermalcapacity理解说明热容量3-describeanexperimenttomeasurethespecificheatcapacityofasubstance描述一个实验测量一个物体的比热容量。(d) Meltingandboiling熔化和沸腾1-describemeltingandboilingintermsofenergyinputwithoutachangeintemperature温度不变时用吸收的能量描述融化和沸腾2-statethemeaningofmelting

31、pointandboilingpoint描述熔点和沸点的意义3-describecondensationandsolidification描述液化和凝固4-distinguishbetweenboilingandevaporation区分沸腾和蒸发5-usethetermslatentheatofvaporizationandlatentheatoffusionandgiveamolecularinterpretationoflatentheat用蒸发潜热和熔化潜热和给定的分子解释潜热。6-describeanexperimenttomeasurespecificlatentheatsfors

32、teamandforice描述一个测量水流和冰的浅比热。2.3 Transferofthermalenergy热能的传递(a) Conduction传导1-describeexperimentstodemonstratethepropertiesofgoodandbadconductorsofheat描述一个热导体性能好坏的实验。2-giveasimplemolecularaccountofheattransferinsolids给出在固体中一个简单分子热能的转移。(b) Convection对流1-relateconvectioninfluidstodensitychangesanddesc

33、ribeexperimentstoillustrateconvection液体密度的改变和转换的关系，描述一个实验解释转换。(c) Radiation辐射1-identifyinfra-redradiationaspartoftheelectromagneticspectrum辨认红外辐射是电磁光谱的一部分。2-describeexperimentstoshowthepropertiesofgoodandbademittersandgoodandbadabsorbersofinfra-redradiation描述一些实验证明红外辐射好的和坏的释放者和吸收者。(d) Consequencesof

34、energytransfer能量转移的结果1-identifyandexplainsomeoftheeverydayapplicationsandconsequencesofconduction,convectionandradiation辨认和解释生活中传导，转换和辐射的应用和结果。3. Propertiesofwaves,includinglightandsound波的性质包括光和声3.1 Generalwaveproperties普通波的性质1-describewhatismeantbywavemotionasillustratedbyvibrationinropes,springsan

35、dbyexperimentsusingwaterwaves通过用波动的意义解释绳子，弹簧和水波的振动试验2-usethetermwavefront用波振面3-givethemeaningofspeed,frequency,wavelengthandamplitude给出速率，频率，波长和幅度的意义。4-recallandusetheequationv=f入记住和应用等式速率=平率x时间5-distinguishbetweentransverseandlongitudinalwavesandgivesuitableexamples区分横波和纵波并且举出合适的例子。6-describetheuse

36、ofwaterwavestoshow用水波描述(i) reflectionataplanesurface平面反射(ii) refractionduetoachangeofspeed折射由于速率的改变。(iii) diffractionproducedbywideandnarrowgaps通过宽的或窄的缝隙产生衍射。7-interpretreflection,refractionanddiffractionusingwavetheory用波的理论解释反射，折射和衍射。3.2 Light光(a) Reflectionoflight光的反射1-describetheformation,andgive

37、thecharacteristics,ofanopticalimagebyaplanemirror描述形成，给出特点在平面镜中呈现的光学图像。2-usethelawangleofincidence=angleofreflection会用入射角等于反射角3-performsimpleconstructions,measurementsandcalculations演示简单的结构测量和计算。(b) Refractionoflight光的衍射1-describeanexperimentaldemonstrationoftherefractionoflight描述一个实验解释光的衍射现象。2-uset

38、heterminologyfortheangleofincidenceiandangleofrefractionranddescribethepassageoflightthroughparallel-sidedtransparentmaterial会用术语入射角i折射角r并且描述光通过两个透明的平行板。3-givethemeaningofcriticalangle给出一些重要角度的意义。4-describeinternalandtotalinternalreflection描述内部的和总的反射5-recallandusethedefinitionofrefractivenintermsofs

39、peed记住和应用以速度定义折射率n.6-recallandusetheequationsini/sinr=n记住和应用等式sini/sinr=n7-describetheactionofopticalfibres描述纤维光学的作用。(c) Thinconverginglens薄的汇聚透镜1-describetheactionofathinconverginglensonabeamoflight描述薄聚焦透镜对一束光的作用。2-usethetermprincipalfocusandfocallength会用主焦点和焦距。3-drawraydiagramstoillustratetheforma

40、tionofarealimagebyasinglelens用光线图来解释通过单镜头形成的实相。4-drawraydiagramstoillustratetheformationofavirtualimagebyasinglelens画光线图来解释通过单镜头形成的虚像。5-useanddescribetheuseofasinglelensasamagnifyingglass用和描述利用一个单镜头作为一个放大镜。(d) Dispersionoflight光的分散1-giveaqualitativeaccountofthedispersionoflightas川ustratedbytheaction

41、onlightofaglassprism定性的分析当光通过棱镜分散的行为(e) Electromagneticspectrum电磁波谱1-describethemainfeaturesoftheelectromagneticspectrumandstatethatalle.m.wavestravelwiththesamehighspeedinvacuo描述电磁波的主要特点和描述所有的波以同样的速度在真空中传播。2-statetheapproximatevalueofthespeedofelectro-magneticwaves描述电磁波速度值。3-usethetermmonochromatic

42、用单一的一色的。3.3 Sound声音1-describetheproductionofsoundbyvibratingsources描述声音是由振动产生。2-describethelongitudinalnatureofsoundwaves描述声音的纵向特性。3-statetheapproximaterangeofaudiblefrequencies描述可听得见波的大概频率。4-showanunderstandingthatamediumisrequiredinordertotransmitsoundwaves展示和理解声音的传播需要介质。5-describeanexperimenttode

43、terminethespeedofsoundinair描述一个测量声音在空气中传播的速度。6-relatetheloudnessandpitchofsoundwavestoamplitudeandfrequency声波的响度和音调与振幅和频率之间的关系。7-describehowthereflectionofsoundmayproduceanecho描述声音的反射产生回声。8-describecompressionandrarefaction描述压缩和稀疏9-statetheorderofmagnitudeofthespeedofsoundinair,liquidsandsolids描述液体和

44、固体在空气中传播速率大小的顺序。4. Electricityandmagnetism电和磁4.1 Simplephenomenaofmagnetism简单的磁现象1-statethepropertiesofmagnets描述磁体的性质。2-giveanaccountofinducedmagnetism说明感生磁性3-distinguishbetweenferrousandnonferrousmaterials区分含铁和不含铁的材料。4-describemethodsofmagnetisationandofdemagnetisation描述磁化和消除磁性的方法。5-describeanexper

45、imenttoidentifythepatternoffieldlinesroundabarmagnet描述一个实验来辨认一个条形磁铁周围的场线图案。6-distinguishbetweenthemagneticpropertiesofironandsteel区分铁和钢的磁性。7-distinguishbetweenthedesignanduseofpermanentmagnetsandelectromagnets区分和设计永久磁体和电磁体。4.2 Electricalquantities电学物理量(a) Electriccharge电荷1-describesimpleexperimentst

46、oshowtheproductionanddetectionofelectrostaticcharges描述一个简单的实验证明静电荷的产生和发现2-statethattherearepositiveandnegativecharges描述存在正电荷和负电荷。3-statethatunlikechargesattractandthatlikechargesrepel描述同种电荷排斥，异种电荷吸引。4-describeanelectricfieldasaregioninwhichanelectricchargeexperiencesaforce描述电场是一个电荷受力的区域5-distinguish

47、betweenelectricalconductorsandinsulatorsandgivetypicalexamples区分导体和绝缘体并给出典型的例子。6-statethatchargeismeasuredincoulombs描述电荷由库伦来测量。7-statethedirectionoflinesofforceanddescribesimplefieldpatterns,includingthefieldaroundapointchargeandthefieldbetweentwoparallelplates描述力的方向和简单的场的图案，包括点电荷周围的场和两个平行板之间的场。8-gi

48、veanaccountofchargingbyinduction9-recallandusethesimpleelectronmodeltodistinguishbetweenconductorsandinsulators记住和应用简单的电子模型区分导体和绝缘体。(b) Current电流1-statethatcurrentisrelatedtotheflowofcharge描述电流和流动电荷的关系。2-useanddescribetheuseofanammeter用和描述电流表的用法。3-showunderstandingthatacurrentisarateofflowofchargean

49、drecallandusetheequationl=Q/t理解电流是流动电荷的变化率，记住何用等式I=Q/t4-distinguishbetweenthedirectionofflowofelectronsandconventionalcurrent区分电子的流动方向和传统电流的方向。(c) Electro-motiveforce电动势5-statethatthee.m.f.ofasourceofelectricalenergyismeasuredinvolts描述一个电能源的电动势用伏特测量。6-showunderstandingthate.m.f.isdefinedintermsofene

50、rgysuppliedbyasourceindrivingchargeroundacompletecircuit理解电动势被定义为能源提供的能量迫使电荷环绕整个电路。(d) Potentialdifference电势差1-statethatthepotentialdifferenceacrossacircuitcomponentismeasuredinvolts描述通过一个电路元件的电势差用伏特测量。2-useanddescribetheuseofavoltmeter用和描述电压表的用法。(e) Resistance电阻1-statethatresistance=p.d./currentand

51、understandqualitativelyhowchangesinp.d.orresistanceaffectcurrent描述电阻=电势差/电流并且理解怎样改变电势差和电阻影响电流。2-recallandusetheequationR=V/I记住和用等式R=V/I3-describeanexperimenttodetermineresistanceusingavoltmeterandanAmmeter描述一个实验用电压表和电流表测电阻值。4-relate(withoutcalculation)theresistanceofawiretoitslengthandtoitsdiameter不

52、通过计算联系一个导线的电阻值与他的长度，直径的关系。5-recallandusequantitativelytheproportionalitybetweenresistanceandthelengthandtheinverseproportionalitybetweenresistanceandcross-sectionalareaofawire记住和定性的用电阻和长度成正比和面积成反比。(f) Electricalenergy电能1-recallandusetheequationsP=IVandE=IVt记住&用等式P=I*V和E=I*V*t4.3 Electriccircuits电路(a

53、) Circuitdiagrams电路(b) Seriesandparallelcircuits串联和并联1-drawandinterpretcircuitdiagramscontainingsources,switches,resistors(fixedandvariable),lamps,ammetersvoltmeters,magnetisingcoils,transformers,bells,fusesandrelays画和解释电路图包括电源，开关，电阻器(固定的和变化的)灯泡，电流表,电压表，电磁圈,转换器，电铃，保险丝和延迟.2-understandthatthecurrentat

54、everypointinaseriescircuitisthesame理解串联电路中每一点电流相等.3-givethecombinedresistanceoftwoormoreresistorsinseries给出个电阻串联的总电阻.4-statethat,foraparallelcircuit,thecurrentfromthesourceislargerthanthecurrentineachbranch描述，对于一个并联电路电源的总电流总是大于每一个之路的电流.5-drawandinterpretcircuitdiagramscontainingdiodesandtransistors画

55、和解释电路图包括二极管和晶体三极管.6-recallandusethefactthatthesumofthep.d.sacrossthecomponentsinaseriescircuitisequaltothetotalp.d.acrossthesupply记住和应用串联电路中各用电器电势差之和等于总的电源电势差.7-recallandusethefactthatthecurrentfromthesourceisthesumofthecurrentsintheseparatebranchesofaparallelcircuit记住和应用并联电路电源的总电流等于各个支路电流之和.(c) Act

56、ionanduseofcircuitcomponents作用和用电路元件(d) Digitalelectronics数字电子学1-statethatthecombinedresistanceoftworesistorsinparallelislessthanthatofeitherresistorbyitself描述两个电阻并联的合电阻大于其中的任意一个电阻.2-statetheadvantagesofconnectinglampsinparallelinalightingcircuit说明照明电路中并联灯泡的优点.3-describetheactionofavariablepotential

57、divider(potentiometer)描述分压器的作用.4-describetheactionofthermistorsandlightdependentresistorsandshowunderstandingoftheiruseasinputtransducers描述热敏电阻和光敏电阻的作用并且理解它们作为输入导体的作用.5-describetheactionofacapacitorasanenergystoreandshowunderstandingofitsuseintimedelaycircuits描述电容作为能量储存的作用和理解它在延迟电路中的作用.6-describetheactionofarelayandshowunderstandingofitsuseinswitchingcircuits描述延迟的作用和理解它在开关电路中的作用.7-calculatetheeffectiveresistanceoftworesistorsin