图LT4-15所示电路,已知场效应管的g_m、三极管的β、r_bc及各电阻值,r_ds与r_ce忽略不计.(1)试指出放大电路由哪两种组态组合而成.(2)写出R₁、R₀、A_v的表达式.

A . 1mA/V B . 0.5mA/V C . -1mA/V D . -0.5mA/V

<img src='https://img2.soutiyun.com/ask/2020-11-03/973274107500927.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' />

图LT4-11所示共集一共发组合电路,已知晶体三极管β₁=β₂=150,V_BE(on)=0.7V,r_ce忽略不计,I_CQ1=1mA,I_CQ2=1.5mA,R_S=1kΩ,试求R₁、A_S、A_CS. <img src='https://img2.soutiyun.com/ask/2020-10-21/972144585685306.jpg' /> <img src='https://img2.soutiyun.com/ask/2020-10-21/972144598933063.jpg' />

包络检波电路如图NP4-30所示，二极管正向电阻R_D=100Ω，F=100-5000Hz。图(a)中，M_amax=0.8;图(b)中M_a=0.3。试求图(a)中电路不产生负峰切割失真和惰性失真的C和R_i2值。图(b)中可变电阻R₂接触点在中心位置时，是否会产生负峰切割失真？ <img src='https://img2.soutiyun.com/ask/2021-02-26/983184189230326.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' />

A．191.5 B． 168.4 C． 155.3 D． 145.5

图LP3-15所示为分压式衰减电路，已知EMOS场效应管工作在非饱和区，若VI=200 mV，μnCoxW／(2l)=0．01mA／V2，VGS(th)=1．5 V，试分别求出VGS=2．5 V、3 V时的VO值，并进行分析。 <img src='https://img2.soutiyun.com/ask/uploadfile/9045001-9048000/7c485c947fb912771aee44885fcbd0d5.jpg' />

<img src='https://img2.soutiyun.com/ask/2021-01-20/980004815669485.jpg' />

电路如图题5.2.5(主教材图5.2. 10a)所示。设R=0.75 kΩ, Rg1=Rg2=240kΩ，Rs=4 kΩ。场效应管的gm =11.3 mS，rds=50 kΩ。试求源极跟随器的源电压增益AUS=Uo/Us,、输入电阻R,和输出电阻R0。 <img src='https://img2.soutiyun.com/ask/2020-06-29/962269380832062.jpg' />

是 否

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' />

图1-8(a)所示电路中已知C点电位Vc=36V，I_s1=7A，I_s2=4A，R₃=14Ω，R₄=8Ω，R₅=12Ω。用基尔霍夫定律求电流I₁。 <img src='https://img2.soutiyun.com/ask/2020-11-09/973802876045447.png' />

电路如图题4.6.2(主教材图4.6.8)所示，设场效应管的参数为g_m1=0.7mS，λ₁=λ₂=0.01V^-1。场效 应管静态工作时的偏置电流I_REF=0.2mA。试求该CMOS共源放大电路的电压增益A_e。 <img src='https://img2.soutiyun.com/ask/2020-11-17/97447865220952.png' />

<img src='https://img2.soutiyun.com/ask/2021-02-24/983009831097799.png' />

计算图P2.4所示电路中的反相器G_M能驱动多少同样的反相器.要求G_M输出的高、低电平符合U_OH≥3.2V,U_OL≤0.25V.已知所有的反相器均为74LS系列TTL电路,输入电流I_IL=0.4mA,I_IH=20μA,I_OL_(max)=-8mA,I_OH(max)=0.4mA. <img src='https://img2.soutiyun.com/ask/2021-01-21/980091690831762.png' />

(1)最大输出功率P_om和效率ƞ各为多少？ (2)晶体管的最大功耗P_Tmax为多少？ (3)为了使输出功率达到P_om,输入电压的有效值约为多少？ <img src='https://img2.soutiyun.com/ask/2021-01-09/97906063889348.png' /> 图p9.2

<img src='https://img2.soutiyun.com/ask/2021-01-09/979039518243448.png' />

<img src='https://img2.soutiyun.com/ask/2021-01-20/980010629267004.jpg' />

<img src='https://img2.soutiyun.com/ask/2020-12-16/977000025341543.png' />

(1)为保证空载时稳压管能安全工作,R₂应选多大？ (2)当R₂按上面原则选定后,负载电阻允许的变化范围是多少？ <img src='https://img2.soutiyun.com/ask/2021-01-09/979064586449268.png' />

电路如图6-2(a)所示，图(b)为电感电压的波形图，已知R=10Ω，L=4 H，电感电流i_L(0)=0，求电流i_L(t)。 <img src='https://img2.soutiyun.com/ask/2020-08-23/967073690265931.png' />

已知所有的反相器均为74LS系列TIL电路,输入电流I_IL=0.4mA, </sub>IH</sub>=20μA,I_OL(max)=8mA,I_OH(max)=0.4mA. <img src='https://img2.soutiyun.com/ask/2021-02-25/983105410062948.png' />

密闭盛水容器如[例87]图(a)所示,已知h₁=0.6m,h₂=1.0m,水银测压计测得△h=0.25m,试求半径R=0.5m的半球形盖AB所受总压力的水平分力和垂直分力. <img src='https://img2.soutiyun.com/ask/2020-09-23/969715549817315.png' /> [例87]图