试求出下图所示电路Q点、Au、Ri和Ro的表达式。

A . -0.8sinwtV B . -0.5sinwtV C . -0.4sinwtV D . -0.25sinwtV

A . A、电压串联 B . B、电压并联 C . C、电流串联 D . D、电流并联

A . 200kΩ，3kΩ，47．5倍 B . 1．25kΩ，3kΩ，47．5倍 C . 1．25kQ，3kΩ，-47．5倍 D . 1．25kΩ，1．5kΩ，-47．5倍

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<img src='https://img2.soutiyun.com/ask/2019-12-02/944168748704533.png' />

<img src='https://img2.soutiyun.com/ask/2020-06-29/962270064181147.jpg' />

8位倒T型网络D/A转换器电路图如图所示，试求出输出模拟量V_o的表达式。 <img src='https://img2.soutiyun.com/ask/5478001-5481000/2946e79b1b5d5b7b317555acbdfe177a.jpg' />

理想运放组成的电路如图2-3所示，试导出电路的增益表达式<img src='https://img2.soutiyun.com//1/2021-06-04/991677336315431.jpg' />=？ 并在<img src='https://img2.soutiyun.com//1/2021-06-04/991677361034168.jpg' />时，求出<img src='https://img2.soutiyun.com//1/2021-06-04/991677375284189.jpg' />。 <img src='https://img2.soutiyun.com//1/2021-06-04/99167754600275.jpg' />

<img src='https://img2.soutiyun.com/ask/2020-10-10/971178040642309.png' />

电路如图题12-8所示,已知<img src='https://img2.soutiyun.com/ask/2020-07-24/964456047991613.png' />,试分别求出在下列us(t)时的电压u2(t),t≥0 (1)<img src='https://img2.soutiyun.com/ask/2020-07-24/964456140274891.png' />

电路如图题2.1.1所示，运放的开环电压增益A_vo=10⁶，输入电阻r_i=10⁹Ω，输出电阻r_o=75Ω，V₊=+10V，V_-=-10V。(1)求运放输出电压为饱和值时输入电压的最小幅值v_p-v_n=？(2)输入电流i_I=？ <img src='https://img2.soutiyun.com/ask/uploadfile/5517001-5520000/2f87045a8aecd663eed5619b334a0284.png' />

<img src='https://img2.soutiyun.com/ask/uploadfile/5517001-5520000/e25ef4161f32fc367998225c28274214.png' />

七段显示译码电路如下图(a)所示，对应下图(b)所示输入波形，试确定显示器显示的字符序列是什么？ <img src='https://img2.soutiyun.com/ask/uploadfile/5517001-5520000/5de4593ecb3f40de047a058b0d377383.png' />

<img src='https://img2.soutiyun.com/ask/2020-09-17/969211143340094.png' />

<img src='https://img2.soutiyun.com/ask/2020-09-23/969705185060485.png' />

图5-11所示反相输入运放电路，若要求<img src='https://img2.soutiyun.com/ask/2020-06-12/960828077508376.png' />，输入电阻ri>20kΩ，试选配外接电阻R1、R2、RF的阻值。 <img src='https://img2.soutiyun.com/ask/2020-06-12/960828125975148.png' />

分别判断图P2.2(a)、(b)所示两电路各属哪种放大电路,并写出Q、A_u、R_i和R₀的表达式. <img src='https://img2.soutiyun.com/ask/2021-01-09/979034368257886.png' /> <img src='https://img2.soutiyun.com/ask/2021-01-09/979034378158452.png' />

<img src='https://img2.soutiyun.com/1/2020-10-20/972035165109066.png' />