文档介绍：该【华南理工大学《电工学》考试真题5 】是由【小屁孩】上传分享，文档一共【7】页，该文档可以免费在线阅读，需要了解更多关于【华南理工大学《电工学》考试真题5 】的内容，可以使用淘豆网的站内搜索功能，选择自己适合的文档，以下文字是截取该文章内的部分文字，如需要获得完整电子版，请下载此文档到您的设备，方便您编辑和打印。:..华南理工大学《电工学》考试真题5华南理工大学期末考试《电路与电子技术》(双语)试卷B考试时间:120minutesDate:January,15,2013注意事项:;;:闭卷;,满分100分,考试时间120分钟。,findcurrentI,IandIinKCL.(6scores)123????I1A3I2IR???=1-3=-2A213I=-?6=-1A4312?6I=-I-1=1-1=,.(8scores),D截止12(12?3)得I=0,I=mA=5mA213:..=9V,I=3A,R=3?,R=6?.SS12DeterminecurrentI,Iinsuperposition,whichelementsaresupplyingpower?(812scores)..+I"US2-原I'I'1I"R=22S1图RRI12RS..1RI单独作用时:I??2?I?2AI'=1A2S1R?RS212UU单独作用时:I???I???S?1A4S12R?R12叠加得:I=I'+I"=3AI=I'-I"=0111222P?UI?27WP?(RI)I?0US1I22SP?I2R?27WP?=10V,U=20V,S1S2R=R=R=R=R=2?.DeterminecurrentIinthevenintheorem.(10scores)+24+UUS1S2-..-:..I+U0-R3R0RRU=2?U?4?U=?5V40R?RS1R?RS21245R=R//R+R//R=2?701245UI=0=??,R=60?,R=120?,R=40?,L=4H,123U?24V,U?,andthenclosedS1S2att=0,pleasefindthei(t)afterSisclosed.(10scores)LRR1S3+i+LURLUS12S2--(0)?i(0)?S2??L?R3UUi(?)?S1?S2?(叠加原理)4LRR13L???//R//R123t?i(t)?i(?)?i(0)?i(?)e?LLL?L???:v?3182cos(10000t)V,R=R=1?,L=,C=100?:i(t),the12powerfactorandaveragepowerofthetotalcircuit.(10scores):..i+RL1vR2C-?3182?0?V?jR/?CZ?R?j?L?2?159.?184.??31R?j/?C2VI??2002???A5Zi?2002cos(10000t??)A6Powerfactor:???:P???-=24+18j?.FindthelinecurrentofIa,Ia,Ia,(10scores)abZZZ设:U=380?0?VZ=R?jX=30???2ABLUI?AB????A4ABZI=3??(???30?)=???A6A因为:负载为三相对称负载所以:I???AI???A8BC:..:R=R=RR=R=R,findthe123F1F2F3relationshipbetweenuandu.(scores10)oIRF1RF2R1uIu?OR2uRR1F3R3u??u?uOOI由u??u?OO得u??u?uOOIu1故u?I?,assumethat:β=40,r=1kΩ,πdetermine:(1)plotsmallsignalequivalentcircuit;(2)calculateinputresistorrandioutputresistorr;(3)voltagegainA。(10scores).ouUCC?12VR120k?B+TCC+1+2+RuERiLu3k??o--(1):..ibic+?irbbeuiR+BRRuELo--?????????????(2)r?R//r?1?R//R?120//1?1?403//???iBbeEL?1????R//R?(3)A?EL?1ur??1????R//R?-sourceamplifierillustratedinFigure10,(1)plotsmallsignalequivalentcircuit;(putethevoltagegain,inputresistance,andoutputresistance.(10scores).VDDVDDRDRC21ioRC1M1RvoLvinR2RSCv(t)SFigure10RiDioinGv(t)v(t)RRgvrRvRin12vgsmgsdDoLSSRGR?L4Wedenotetheequivalentresistanceby1R'?L1/r?1/R?1/RdDLTheoutputvoltageistheproductofthecurrentfromthecontrolledsourceandtheequivalentresistance::..v??(gv)R'0mgsLTheinputvoltageandthegate-to-sourcevoltageareequal:v?vingsweobtainthevoltagegain:vA?o??gR'vvmLin6InputResistancevR?in?R?RRiniG12in8OutputResistanceRGDRv??01/R?1/,an’slaw,analyzeitslogicfunction.(8scores)?ABAB?ABAB?AB(A?B)?(A?B)(A?B)?AA?BB?AB?AB?AB?AB是“异或”门