在图P9.2所示电路中,已知V_cc=16V,R_L=4Ω,T1和T2管的饱和压降|U_CES|=2V,输入电压足够大.试问:

A . 1 B . 2 C . 3 D . 不能确定

A . 100 B . 220 C . 161 D . 142

A . -1 B . 0 C . 1 D . 不能确定

<img src='https://img2.soutiyun.com/shangxueba/ask/18489001-18492000/18491351/2015110114454662221.jpg' /> A．6 B． 9 C． 12 D． 5

在图6.3.7所示电路中，已知u_S1=20V，<img src='https://img2.soutiyun.com/ask/2020-02-27/951670632845205.png' />，求I。 <img src='https://img2.soutiyun.com/ask/2020-02-27/951670670400982.png' />

在图NPSI-4(a)所示甲类变压器耦合功率放大器原理电路中，若晶体管采用NSC-4A，V_cc=20V，基极直流偏置电压V_BB=0.8V，R_L=3.9Ω，L₁(W₁)=10mH，L₂(W₂)=90mH，变压器耦合系数k=0.9999。当输入信号v_i(t)=0.1cos(2πx10³t)(V)时，试画出输出电压波形，并求二次、三次谐波失真系数。 <img src='https://img2.soutiyun.com/ask/2021-02-24/983010057840768.png' />

在图4.4.1(a)和(b)所示的互补对称电路中，已知Vcc=6V，R_L=8Ω，假设三极管的饱和管压降U_CES=1V。 ①试估算电路的最大输出功率P_om; ②估算电路中直流电源消耗的功率P_V和效率η。 并将两个电路的估算结果进行比较。 <img src='https://img2.soutiyun.com/ask/2020-09-10/968622476866462.png' />

在图2.4.3所示的射极输出器电路中，设三极管的β=100，Vcc=12V，R_e=5.6kΩ，R_b=560kΩ，r_bb’=300Ω。 ①求静态工作点; ②分别求出当R_L=∞和R_L=1.2kΩ时的 <img src='https://img2.soutiyun.com/ask/2020-09-10/96862189830037.png' /> ③分别求出当RL=∞和RL=1.2kΩ时的Ri; ④求R0。 <img src='https://img2.soutiyun.com/ask/2020-09-10/968621904984752.png' />

在图3-23所示的电路中，已知<img src='https://img2.soutiyun.com/ask/2020-11-14/974192768614519.png' />试求I₃。 <img src='https://img2.soutiyun.com/ask/2020-11-14/974192781086232.png' />

<img src='https://img2.soutiyun.com/ask/2020-09-11/9687068705288.png' />

<img src='https://img2.soutiyun.com/ask/2020-12-31/97825836893139.png' />

在图3.17所示电路中，已知R=2Ω，Z₁=-j10Ω，Z₂=(40+j30)Q，<img src='https://img2.soutiyun.com/ask/2020-12-15/976893137697925.png' /><img src='https://img2.soutiyun.com/ask/2020-12-15/976893148823561.png' /> <img src='https://img2.soutiyun.com/ask/2020-12-15/976893181116408.png' />

在图5-2-3所示轮系中，已知<img src='https://img2.soutiyun.com/ask/2021-01-24/980354250160352.png' />若n₁=500r/min，求齿条6线速度v的大小和方向。 <img src='https://img2.soutiyun.com/ask/2021-01-24/980354261270988.png' />

<img src='https://img2.soutiyun.com/shangxueba/ask/18513001-18516000/18515934/2015110113421330164.jpg' /> A．100 B． 220 C． 161 D． 142

(1)试校核电路中各整流桥所选用的二极管型号是否合适。 (2)若将绕组2-2'的极性接反,对整流电路有无影响,为什么？ (3)若将a,b间连线去掉,电路是否仍能工作？ 此时输出电压U.和输出电流I等于多少？所选用的二极管是否合适？ <img src='https://img2.soutiyun.com/ask/2020-10-07/970947346109041.png' /> <img src='https://img2.soutiyun.com/ask/2020-10-07/970947381564069.png' />

在图LP3-2所示电路中,假设两管p₀、C_ok相同,V_GS(th)=0.75V,I_D2=1mA若忽略沟道长度调制效应,并设T₁管的沟道宽长比(W/l)是T₂管的5倍.试问流过电阻R的电流I_R值. <img src='https://img2.soutiyun.com/ask/2020-10-21/972140154936881.png' />

在图LP4-69所示的共集电极电路中,已知晶体三极管在I_CQ=2mA时的参数为r_bb=50Ω,<img src='https://img2.soutiyun.com/ask/2020-10-26/97255806712955.png' />试求高频电压传递函数<img src='https://img2.soutiyun.com/ask/2020-10-26/972558082050404.png' />的表示式. <img src='https://img2.soutiyun.com/ask/2020-10-26/972558092714014.png' />

<img src='https://img2.soutiyun.com/ask/2020-09-14/968971604757546.png' />

①试估算电压放大倍数和 <img src='https://img2.soutiyun.com/ask/2020-09-10/968621949195281.png' />输入、输出电阻R_i、R₀; ②如果不接旁路电容Ca，则=？ <img src='https://img2.soutiyun.com/ask/2020-09-10/968621959958897.png' />

<img src='https://img2.soutiyun.com/ask/2021-02-26/983184210538544.png' />

在图NT6-4所示锁相解调电路中，若将环路滤波器改为简单RC滤波器，则当环路的输入信号v_i(t)=V_imsin(ω_rt+M_fsin_Ωt)时，试证:为实现不失真解调，必须满足下列关系式<img src='https://img2.soutiyun.com/ask/2021-02-26/983187125725284.png' /> <img src='https://img2.soutiyun.com/ask/2021-02-26/983187147945554.png' />

<img src='https://img2.soutiyun.com/ask/2021-02-02/981105835723253.png' />

<img src='https://img2.soutiyun.com/ask/2021-02-02/981108704506338.png' /><img src='https://img2.soutiyun.com/ask/2021-02-02/981108782575804.png' />