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

放大电路如下图所示，β₁=β₂=50，静态电流I_C1≈I_C2=1mA，r_be1=r_be2=1.5kΩ，两管均工作在放大状态，试求电压增益<img src='https://img2.soutiyun.com/latex/latex.action' />。 <img src='https://img2.soutiyun.com/ask/5466001-5469000/8a85be8fb9a3b5fd116d56e9b55c2f9d.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' />

<img src='https://img2.soutiyun.com/ask/2020-08-31/967720818304797.png' />

<img src='https://img2.soutiyun.com/ask/2020-08-24/967136357397162.png' /><img src='https://img2.soutiyun.com/ask/2020-08-24/967136393334217.png' /><img src='https://img2.soutiyun.com/ask/2020-08-24/96713640161069.png' /> <img src='https://img2.soutiyun.com/ask/2020-08-24/96713641297734.png' />

在题2．27图所示电路中，对称负载连成三角形，已知电源电压UL=220 V，各电流表读数均为38 A。试求(1)当B线断开时，图中各电流表的读数；(2)当AC相负载断开时，图中各电流表的读数。 <img src='https://img2.soutiyun.com/ask/uploadfile/10374001-10377000/b1d6841abcf8b603feda441232220fc4.jpg' />

<img src='https://img2.soutiyun.com/ask/2020-07-06/962894436190544.png' /><img src='https://img2.soutiyun.com/ask/2020-07-06/962894441876869.png' />

题图10-50所示单口网络工作于正弦稳态，已知us(t)=<img src='https://img2.soutiyun.com/ask/2020-07-07/96297017944186.png' />试求单口网络的戴维宁等效电路。 <img src='https://img2.soutiyun.com/ask/2020-07-07/962970193210647.png' /><img src='https://img2.soutiyun.com/ask/2020-07-07/962970201021094.png' /><img src='https://img2.soutiyun.com/ask/2020-07-07/962970211392687.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' />

题图7-8(a)所示单口网络可以等效为题图7-8(b)所示的单口网络，试求等效电感L和等效电容C的数值。 <img src='https://img2.soutiyun.com/ask/2020-07-07/962960510256814.png' />

<img src='https://img2.soutiyun.com/shangxueba/ask/50805001-50808000/50806402/967198328638004.png' />

<img src='https://img2.soutiyun.com/ask/2020-08-25/967204245200412.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' />

如习题7-29图所示,一长为l的细长直杆，水平放置，杆上均匀带电,电荷量为q。试求:(1)在杆的延长线上任意一点的电势和电场强度;(2)在杆的垂直平分线上任意一点的电势和电场强度。 <img src='https://img2.soutiyun.com/ask/2020-07-16/963761504123945.png' />

在匀强电场E中,有一半径为R的闭合半球面,其底面与电场线垂直，如习题7-14图所示。试求:(1)分别通过闭合半球面底面和球面的电场强度通量;(2)半球面内的总电荷量。 <img src='https://img2.soutiyun.com/ask/2020-07-16/963760710032525.png' />

试求题9-12图所示电路的零状态响应i₁(t)和i₂(t). <img src='https://img2.soutiyun.com/ask/2020-10-10/971200443931704.jpg' />

设某系统中N个粒子的速率分布曲线如习题5-13图所示。试求:(1)常量A以v0表示;(2)速率在0~v0之间、1.5 v0~2 v0之间的粒子数;(3)粒子的平均速率;(4)速率在0~v0之间粒子的平均速率。 <img src='https://img2.soutiyun.com/ask/2020-07-16/963757549190736.png' />

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' />

<img src='https://img2.soutiyun.com/ask/2020-10-11/971295964907616.jpg' />

<img src='https://img2.soutiyun.com/ask/2020-10-07/970904369406914.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' />

假定练习题4-3图(a)所示电路中，器件A的伏安特性曲线如练习题4-3图(b)所示.试求在下列三种情况下10Ω电阻的电压： <img src='https://img2.soutiyun.com/ask/2020-08-24/967136242730603.png' /><img src='https://img2.soutiyun.com/ask/2020-08-24/967136250058022.png' /> <img src='https://img2.soutiyun.com/ask/2020-08-24/967136258148485.png' /> (1)Us=2V时; (2)Us=1/2V时; (3)Us=-2V时。

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

<img src='https://img2.soutiyun.com/ask/2020-08-24/967136592941634.png' /><img src='https://img2.soutiyun.com/ask/2020-08-24/967136602053155.png' /><img src='https://img2.soutiyun.com/ask/2020-08-24/967136609348572.png' /><img src='https://img2.soutiyun.com/ask/2020-08-24/967136618306084.png' /> <img src='https://img2.soutiyun.com/ask/2020-08-24/967136626942578.png' />

电路如题6-6图所示，其中R=2，L=1 H，C=0.01 F，uc(0)=0若电路的输人电流为 <img src='https://img2.soutiyun.com/ask/2020-08-23/967074442967253.png' /> <img src='https://img2.soutiyun.com/ask/2020-08-23/967074454682874.png' /> 试求两种情况下，当1＞0时的u_R、u_L和u_C值。 <img src='https://img2.soutiyun.com/ask/2020-08-23/967074466148894.png' />