自耦变压器电路如练习题11-17图所示，若U_ac=220V，U_bc=200V，试求流过绕组的电流。

A．<img src='https://img2.soutiyun.com/latex/latex.action' /> B．<img src='https://img2.soutiyun.com/latex/latex.action' /> C．110V D．220V <img src='https://img2.soutiyun.com/ask/5451001-5454000/d42e728a39bc016169f4ef76bc68bf63.jpg' />

电路如习题4-5图所示，其中R=2Ω，L=1H，C=0.01F，u_C=0，若电路的输入电流为 <img src='https://img2.soutiyun.com/ask/uploadfile/5361001-5364000/1dc19a2e7111fdeba57ad82a24868489.png' />

在题1.2图所示的RLC串联电路中，己知<img src='https://img2.soutiyun.com/ask/2020-12-23/977600078082618.png' />求i、u_R和u_L。 <img src='https://img2.soutiyun.com/ask/2020-12-23/977600113222628.png' />

<img src='https://img2.soutiyun.com/shangxueba/ask/18198001-18201000/18200839/2017060615030773241.jpg' /> A．最大输出电压Um B． 最小大输出电流Im C． 最大输出电流Im D． 最大输出电压Umi

练习题4-12图所示电路;(1)试求单口网络N₂的等效电阻;(2)求出当N₂与N₁相连时的端口电压u₂;(3)试用置换定理求电压u_o。 <img src='https://img2.soutiyun.com/ask/2020-08-24/967136830775237.png' />

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试求题4-25图所示电路中电容电压u_c(t)在t＞0时的函数式.已知u_c(0_)=80V. <img src='https://img2.soutiyun.com/ask/2020-10-09/971120741399575.png' />

在题5-12图所示电路中,若电流i(t)=1sin314tA,试求电压u_R(t)、u_L(t)、u_c(t)和u(t),并绘出波形图和相量图. <img src='https://img2.soutiyun.com/ask/2020-10-10/971172831541366.png' />

电路如练习题8-12图所示，已知u_s=100cos(20t)V。 (1)计算<img src='https://img2.soutiyun.com/ask/2020-08-28/967470801948578.png' /> (2)绘相量图表面(1)中各相量; (3)求<img src='https://img2.soutiyun.com/ask/2020-08-28/967470841053815.png' />的相位关系; (4)写出i、u_ab、u_bc及u_cd。 <img src='https://img2.soutiyun.com/ask/2020-08-28/96747081020605.png' />

在题6.8图所示电路中,求开关S闭合瞬间t(=0)电路小的电压u_C、u_L。 <img src='https://img2.soutiyun.com/ask/2020-10-07/970927159291421.png' />

在题5-7-5图所示的电阻电感串联电路中,若电流i(t)=0.8Ssin314t A,试求电压u_R(t)、u_L(t)和u(t),并绘出波形图和相量图. <img src='https://img2.soutiyun.com/ask/2020-10-10/971171923335419.png' />

对于题1-19图所示电路,(1)当端口电压U_ab=50V时,求输出电压<img src='https://img2.soutiyun.com/ask/2020-10-09/971093340927358.png' /><img src='https://img2.soutiyun.com/ask/2020-10-09/971093352207003.png' />(2)计算端口等效电阻R_ab. <img src='https://img2.soutiyun.com/ask/2020-10-09/971093371271093.png' />

电路如题1-11图所示，试求(1)图(a)中电流i₁和电压u_ab;(2)图(b)中电压u_cb。 <img src='https://img2.soutiyun.com/ask/2020-08-20/966768174350855.png' /><img src='https://img2.soutiyun.com/ask/2020-08-20/966768181740278.png' />

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电路如题6-17图所示，在t＜0时.电路已处于稳态，t=0时开关S由1端接至2端，求t＞0时的电容电压u_c(t)。 <img src='https://img2.soutiyun.com/ask/2020-08-20/966785880595594.png' />

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电路如练习题8-13图所示，已知i_s(t)=cos(t+90°)A，试求稳态电压u(t)，并绘相量图。 <img src='https://img2.soutiyun.com/ask/2020-08-28/967470947804921.png' />

已知电路如题7-11图所示.输入电压为u_i(t)=(10sin200t+10sin400t+10sin800t)V若要使输出电压u₀(t)中仅包含角频率为200rad/s的谐波分量,问L、C应取何值？ <img src='https://img2.soutiyun.com/ask/2020-10-10/971183075841306.jpg' />

练习题6-5图所示RL电路，已知u_s(t)=12e(t)V试求阶跃响应i_L、u₁和u。 <img src='https://img2.soutiyun.com/ask/2020-08-25/967204134099058.png' />

电路如题10-1图所示,已知<img src='https://img2.soutiyun.com/ask/2020-08-21/966851847824976.png' />:求电容电流i_c. <img src='https://img2.soutiyun.com/ask/2020-08-21/966851861353749.png' />