一无限长的直导线和一正方形的线圈如题11.16图所示放置（导线与线圈接触处绝缘).求:线圈与导线

放大电路如题A-45图所示，已知β、r_bc、g_m。 <img src='https://img2.soutiyun.com/ask/2019-11-10/94224624022542.png' />

<img src='https://img2.soutiyun.com/ask/2020-12-08/976298945460063.png' />

<img src='https://img2.soutiyun.com/ask/2020-07-10/963227378433887.png' />

对于 如题3-6图所示的三角波信号，试证明其频谱函数为<img src='https://img2.soutiyun.com/ask/2020-07-10/963220577029868.png' />。 <img src='https://img2.soutiyun.com/ask/2020-07-10/963220592031727.png' />

<img src='https://img2.soutiyun.com/shangxueba/ask/17865001-17868000/17866529/2015110210021760004.jpg' /> A．四进制减法计算器 B． 四进制加法计算器 C． 八进制减法计算器 D． 八进制加法计算器

<img src='https://img2.soutiyun.com/shangxueba/ask/17868001-17871000/17870043/2015110210025158108.jpg' /> A．<img src='https://img2.soutiyun.com/shangxueba/ask/17868001-17871000/17870043/2015110210031265788.jpg' /> B．<img src='https://img2.soutiyun.com/shangxueba/ask/17868001-17871000/17870043/2015110210032979940.jpg' /> C．<img src='https://img2.soutiyun.com/shangxueba/ask/17868001-17871000/17870043/2015110210034421002.jpg' /> D．<img src='https://img2.soutiyun.com/shangxueba/ask/17868001-17871000/17870043/2015110210035895254.jpg' />

<img src='https://img2.soutiyun.com/ask/2021-02-14/982167363192026.png' />

<img src='https://img2.soutiyun.com/ask/2020-07-10/96322419439877.png' />

(1)任一时刻线圈内所通过的磁通量; (2)线圈中的感应电动势. <img src='https://img2.soutiyun.com/ask/2020-12-28/978021556821525.png' />

一无限长导线通以<img src='https://img2.soutiyun.com/ask/2020-04-23/956505514239629.png' />的电流，式中I0和α均为常量，紧靠长直线有一矩形线圈，长直导线与线圈共面，直导线和线圈的互感系数为()，线圈内的互感电动势为()。

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' />

<img src='https://img2.soutiyun.com/ask/2020-08-21/966849722889436.png' />

<img src='https://img2.soutiyun.com/ask/2020-09-23/969707625128049.png' />

长直导线载有电流i=Imsinwt,在其附近有一矩形线框，如题4-1-1图所示。求线框中的感应电动势。 <img src='https://img2.soutiyun.com/ask/2020-07-03/962616315432341.png' />

<img src='https://img2.soutiyun.com/ask/2021-02-20/982709794204926.png' />

<img src='https://img2.soutiyun.com/ask/2020-08-20/966767899910158.png' />

<img src='https://img2.soutiyun.com/ask/2020-08-20/966783342890446.png' />

<img src='https://img2.soutiyun.com/ask/2020-08-20/966767250361006.png' />

一无限长圆柱面,其电荷面密度为<img src='https://img2.soutiyun.com/ask/2020-04-30/957107726124018.png' />.式中<img src='https://img2.soutiyun.com/ask/2020-04-30/957107739133835.png' />为半径R与x轴所夹的角，如图5-21所示。试求圆柱轴线上一点的场强。 <img src='https://img2.soutiyun.com/ask/2020-04-30/957107750785014.png' />

<img src='https://img2.soutiyun.com/ask/2020-09-22/96964827678019.png' />