图3－19所示电路中开关S1在t=0时闭合，开关S2在t=1s时闭合，试用阶跃函数表示电流i（t)。

A . 6.67（1-） B . 10V C . 10（1-） D . 6.67+3.33

A . 126e-3 B . 126（1-e-3） C . 126（1+e-3） D . 4-3e-3

A . 如图A B . 如图B C . 如图C D . 如图D

A . 1 B . 0.5 C . 2 D . 0.25

A .https://assets.asklib.com/psource/2015110111290284798.jpg B .https://assets.asklib.com/psource/201511011129155823.jpg C .https://assets.asklib.com/psource/2015110111293084231.jpg D .https://assets.asklib.com/psource/2015110111294629263.jpg

A . 0 B . 0.6 C . 0.3 D . 0.03

A . 4.5-0.5https://assets.asklib.com/psource/2015102909090699957.jpg A.B . 4.5-4.5https://assets.asklib.com/psource/2015102909090699957.jpg A.C . 3+0.5https://assets.asklib.com/psource/2015102909090699957.jpg A.D . 4.5-0.5https://assets.asklib.com/psource/2015102909090699957.jpg A.

A . A B . B C . C D . D

A .https://assets.asklib.com/psource/201511020947074085.jpg B .https://assets.asklib.com/psource/2015110209472042024.jpg C .https://assets.asklib.com/psource/2015110209473654095.jpg D .https://assets.asklib.com/psource/2015110209474940538.jpg

如图5.4.10所示电路中，t＜0时，电路已处于稳态，t=0时开关闭合，求t≥0₊时ic(t)。 <img src='https://img2.soutiyun.com/ask/2020-02-27/951671752554798.jpg' />

<img src='https://img2.soutiyun.com/ask/2020-06-17/961264067053561.png' />

<img src='https://img2.soutiyun.com/shangxueba/ask/18495001-18498000/18496804/2015110114005030374.jpg' /> A．0 B． 0.6 C． 0.3 D． 0.03

<img src='https://img2.soutiyun.com/shangxueba/ask/18525001-18528000/18526549/201511011401317578.jpg' /> A．2.5 B． -2 C． 2 D． -2.5

在题6-13图电路中，开关S闭合于1端已经很久，t=0时开关S由1端接至2端，求t＞0的电容电压uc(t)和电流i(t)。 <img src='https://img2.soutiyun.com/ask/2020-08-20/966785347664113.png' />

电路如图题6-33所示,求<img src='https://img2.soutiyun.com/ask/2020-10-15/971631143700658.png' /><img src='https://img2.soutiyun.com/ask/2020-10-15/971631160210602.png' />已知开关在t=0时闭合,闭合前电路已处于稳态. <img src='https://img2.soutiyun.com/ask/2020-10-15/971631172391299.png' />

电路如图所示，Is=3A，Us=18V，R1=3Ω，R2=6Ω，L=2H，在t＜0时电路已处于稳态。当t=0时开关S闭合，求t≥0时的i_L、u和i(t)。 <img src='https://img2.soutiyun.com/ask/uploadfile/5499001-5502000/c59f97db78e22204b83620ad1e292af9.jpg' />

电路如题6-4图所示，已知电感电流iL(0_)=0，t=0时闭合开关，求t≥0的电感电流和电感电压。 <img src='https://img2.soutiyun.com/ask/2020-08-20/966784685280226.png' />

题图8-10所示电路中，开关闭合已经很久，t=0时断开开关，试求t>0的电阻电流i(t)。 <img src='https://img2.soutiyun.com/ask/2020-07-07/962962316576129.png' />

图4-4所示电路,t=0时,开关S闭合,求v_c(t). <img src='https://img2.soutiyun.com/ask/2020-12-01/975674141499809.png' />

<img src='https://img2.soutiyun.com/shangxueba/ask/18498001-18501000/18500204/2015110114043515136.jpg' /> A．0 B． -5 C． 5 D． 10

题3.19图所示电路己处于稳态，当t=0时开关S由a切换至b，求t≥0时的电流i(t)和电压uR(t)。 <img src='https://img2.soutiyun.com/ask/2020-09-17/969183881171787.png' />

A．6V B．4V C．0V D．8V

电路如题图8-12所示，开关断开已经很久，t=0时闭合开关，试求t≥0时的电容电压uC(t)。 <img src='https://img2.soutiyun.com/ask/2020-07-07/962962362290744.png' />

题7-2图所示各电路中开关S在t=0时动作，试求各电路在t=0，时刻的电压电流。已知题7-2图(d)中的<img src='https://img2.soutiyun.com/ask/2020-08-24/96707702037258.png' />。 <img src='https://img2.soutiyun.com/ask/2020-08-24/96707704860863.png' />