【题11】:作s域模型,选用节点法,设节点电压U1(s)(电容电压),和节点电压U2(s)(受控源两端电
U1(s)1s112(s?1)(s?3) (?)U(s)?()U(s)?2I(s)I(s)??(s)?压),可得:;;解得U122222s?12ss(?4s?5)Us)?Us)o(2(112(s?3)?2t (t)?7.2?7.58ecos(t?161.57?)(t)V ?;uos?1ss(?2?j)(s?2?j)???【题12】:u;iL(;复频域模型如图 (0)?40V0)?4AC??
604?030.5890.589140s2?204s?601ss?1?)U()s?40????s)?节点方程(得U CC(2s?5s?5s(s?6s?6)ss?1.268s?4.732?1.268t?4.732tu(t)?(10?30.589e?0.589e)V , t?0 C【题13】:u u (0)?0V(0)?1VC2?C1?81224+1UC1(s)+s321s___ss+8+UC2(s)_
5(s?1.2)(s?4)11111 Us()?(??)(Us)??24832248ss(?1)(s?3)818ss2?(12?)s?ss311?4(s?1)(s?3)s3?1?3?t3?3tt3tu?(1?e?e)()tVu?(1?e?e)()tV C1C25s?12.8844UC2(s)?2s(s?1)(s?3)UC1(s)????【题14】:
111?0.4(1??)U()s?? Li(0)?0.4i(0)?0.6A11?1?2262s?2ss2??s3333(.04s?1)(s?3) Us()?ss(?2)(s?4)U111131I(s)???? 26?2s16s40s?280s?411?3?2t4t i?(?e?e)(t)A2164080?【题15】:
U?i(0)?0.9ALi(0)?0.6i(0)?0.A1 Li(0)?0.22?22?1?11?12.s?3
s(s?2)(s?4)31619133?9?2t4tI???(?e?e)(t)A i?
8s40s?240s?482040?或i ?0.375?0.e15?0.225e(t)A【题16】:
?+?2t?4t??IL(s)0.50.5sU(s)_2s12.5s0.5_+
s2?43.960.04044(s?25)22(s?25)12.5(s)???s)?2Us()??2 IL( I Ls2ss?0.5051s?49.495sss(?50s?25)s?50s?252???212.5s?0.505t?49.5t i?(4?3.e96?0.e04)(t)AL?【题17】:
I(s)10?100?s12s13s?40?s?Uc2(s)?
100?4061406424s U I(s)??()s?Is()???C211113ssss?110??s?22s3s12 u()t?(64?24e)()tVC2【题18】:
作s域模型,选用网孔法
t?12?(2?s)I1(s)?sI2(s)?12?2U(s)s1 ?sI1(s)?(s??2)I2(s)?2U(s) 解得:
6(s?4)sU)?2I2(s)?o(s(s?27.)(s?05.6)U(s)?2I1(s)?0.56t?2.7t u(t)?(9.e64?3.e64)(t)VoI2(s)?12(s?4)4s2?13s?6?【题19】:
i u(0)?1V(0)?2AC?L?复频域模型如图
节点方程:(??87s112s?20??U(s)?)Us()?0.1? 得 CC21022.5sss?5s?4s?4s?11?4t?tit()?ut()?(4e?3.e)5A , t?0 C2
第十五章 电路方程的矩阵形式答案 题1
(1)?2(2)?4(3)?56(4)?8?(5)1379
(画错一条(包括方向错误)扣2分,错4条以上则无分) 题2:(C) 题3:(D) 题4:(C) 题5:(C)
?)(0题6:(A) 题7:
题8:
题9:
题10:
duC1duC2diL ??0.5i?0.5i?0.5u?0.5u??0.2u?iLSC1C2C2Ldtdtdt题11:
题12:
题13:
duCdi3 L? 2500u?7500?10i?7500u??u?1000i?uCLSCLSdtdt题14:
第十六章 二端口网络答案
3、典型习题 【题1】:(B) 【题2】:(B) 【题3】:(A) 【题4】:输出端开路时的转移阻抗; 输入端开路时的输出阻抗。 【题5】:
1111R2?R1R2?R1R1?R2 ???????R1?R2? 2222?U1?2? z12??I2?0?I2???z1?1??UU1I?z2I11121?【题6】:? z1??z2?2??U1I1?z2I2I21??U2z22??6? ?1?0?II2?U?2? z21?2?I1?0?I1?I2?0??6?
【题7】:?U1?1?I1?3?0?U3??U1?3I2?U3,得z ,得z11?3? ?12?5?
U3?2I1??U3?2I2U2?2(?3U3)?U3??5U3??U2?2(I2?3U3)?U3?2I2?5U3z21??10?,得;,得 ??U3?2I1U3?2I2??z22??8?
【题8】:(B) 【题9】:(B)
?j?C1?j? C2 【题10】:G ?G ?G G【题11】:
【题12】: