如图所示正弦稳态电路，已知电源U_S的频率为f时，电流表A和A₁的读数分别为0和2A；若U_S的频率变为f/2，而幅值不变，则电流表A的读数为( )。

A . 7V B . 5V C . （R+1）I D . -7V

A . 5 B . 8.6 C . 10 D . 17.3

图题6-14所示电路中电源u_s(t)系一脉冲电压,该电压于t=0时作用于电路,持续1ms,在持续期间脉冲幅度为30V,试求i(t). <img src='https://img2.soutiyun.com/ask/2020-10-15/971628373938237.jpg' />

电路如图题6-37所示，已知i(t)=10A，t≥0;u(0)=1V。求电压u(t)的零输人响应和零状态响应，稳态响应和瞬态响应。 <img src='https://img2.soutiyun.com/ask/2020-08-25/967214993014152.png' />

A．16V，17Ω B．16V，9Ω C．-16V，10Ω D．-16V，9Ω <img src='https://img2.soutiyun.com/ask/uploadfile/5484001-5487000/d82841b01f81c0fd530f8efa2a7ceb0b.png' />

<img src='https://img2.soutiyun.com/ask/2020-10-07/970927824241454.png' />

(1)试定性画出启动后电流i的变化过程; (2)当电流变化已达稳态过程后,试求出电流i的变化过程. <img src='https://img2.soutiyun.com/ask/2020-10-15/971633123415891.jpg' />

电路如图题4-6(a)所示，u_S=12V、R=2kΩ，网络N的VCR如图题4-6(b)所示，求u和i，并求流过两线性电阻的电流。 <img src='https://img2.soutiyun.com/ask/2020-08-27/967409762293118.png' />

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' />

<img src='https://img2.soutiyun.com/ask/2020-10-07/970908982250754.png' />

电路如题图5-7所示，已知电源电压为正弦电压，电流I₁=I₂=10A，试<img src='https://img2.soutiyun.com/ask/2021-01-03/978529327380181.png' />和<img src='https://img2.soutiyun.com/ask/2021-01-03/978529340109909.png' />，设<img src='https://img2.soutiyun.com/ask/2021-01-03/978529340109909.png' />的初相角为零。 <img src='https://img2.soutiyun.com/ask/2021-01-03/978529357270891.png' />

<img src='https://img2.soutiyun.com/ask/2020-10-10/9711752938202.jpg' />

<img src='https://img2.soutiyun.com/ask/2020-08-28/967474712387309.png' />

电路如图所示，已知R=50Ω，L=2.5mH，C=5μF．电源电压U=10V，角频率ω=10⁴rad/s，求电流<img src='https://img2.soutiyun.com/latex/latex.action' />、<img src='https://img2.soutiyun.com/ask/uploadfile/5499001-5502000/d1af2cd2ab3ec9264f1b32c97996ae01.png' /><img src='https://img2.soutiyun.com/ask/uploadfile/5499001-5502000/7953321cf378e46b1e9d47bfb6637091.png' />和<img src='https://img2.soutiyun.com/ask/uploadfile/5499001-5502000/20b08680be5b4effb9d6d2076513acdc.png' />，并画出其相量图。 <img src='https://img2.soutiyun.com/ask/uploadfile/5499001-5502000/bbdcd7c3cadc288f80e41810febcd2b9.png' />

<img src='https://img2.soutiyun.com/shangxueba/ask/18756001-18759000/18757223/2016071815235556431.jpg' /> A．10 B． 12 C． 14 D． 16

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' />

t≥0时电路如图题12-2所示，已知i_L(0_)=-2A，u_c(0_)=2V，试求u_c(t)，t≥0。 <img src='https://img2.soutiyun.com/ask/2020-08-31/967733127072818.png' />

电路如图题7-3所示,当t＜0时,u_s(t)=-1V.在t=0时,u_s(t)突然增至1V,以后即一直保持为此值.试求电路中各元件的电压和电流,并绘波形图. <img src='https://img2.soutiyun.com/ask/2020-10-15/971636130963913.jpg' />

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' />

电路如图P1.3所示,已知u_i=5sinωt(V),二极管导通电压U_D=0.7V.试画出u_i与u₀的波形图,并标出幅值. <img src='https://img2.soutiyun.com/ask/2021-01-08/978983536147222.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' />

<img src='https://img2.soutiyun.com/ask/2020-09-17/96918661355307.png' />

<img src='https://img2.soutiyun.com/ask/2020-10-10/97117883143954.jpg' />