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。

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试用网孔分析求解图题8-10所示电路中的正弦稳态电流i₁(t)和i₂(t)。已知u_s(t)=9cos(5t)V。 <img src='https://img2.soutiyun.com/ask/2020-08-27/967411508475994.png' />

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已知题9-4图所示电路中u_s=16√2sin(ωt+30°)V，电流表A的读数为5A。ωL=4Ω，求电流表A₁、A₂的读数。 <img src='https://img2.soutiyun.com/ask/2020-11-30/975592647422898.png' />

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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' />

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求图题11-6所示电路中的i₁和i₂，已知u_s(t)=100cos(10³+t+30°)V。 <img src='https://img2.soutiyun.com/ask/2020-08-31/967729012341469.png' />

电路如题图5-8所示，已知R₁=10Ω，C=10³μF，R₂=0.5Ω，ω=1000rad/s，<img src='https://img2.soutiyun.com/ask/2021-01-03/978529389968761.png' />求当电流有效值I最大时，电感L为何值？ <img src='https://img2.soutiyun.com/ask/2021-01-03/978529403802552.png' />

题5.6图所示电路已处于稳态，当t=0时开关S由a切换至b，求t≥0时电流i₂(t)，并画出波形图。 <img src='https://img2.soutiyun.com/ask/2020-09-17/969188809236656.png' />

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' />

题7-27图所示电路中，已知i_S=10e(t)A，R₁=1Ω，R₂=2Ω，C=1μF，u_C(0-)=2V，g=0.25s。求全响应i₁(t)、i_C(t)、u_C(t)。 <img src='https://img2.soutiyun.com/ask/2020-09-02/967900598791111.png' />

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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' />

题11-9图所示电路为RC并联电路，己知i_s(t)=ε(t)，用运算法求u_c(t)和i_c(t)。 <img src='https://img2.soutiyun.com/ask/2020-08-21/966853923134676.png' />

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' />

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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' />