# 2021中国大学MOOC 电子学(北京交通大学) 最新中国大学MOOC满分章节测试答案

## 1 电子学基础 第1单元测验

1、 问题:What is the input resistance between terminals B and G in the circuit shown below? (The voltage vx is a test voltage with the input resistance Rin defined as Rin ≡ vx / ix.) A: B: C: D: 2、 问题:A signal source has an open-circuit voltage of 10mV and a short-circuit current of 10μA. The source resistance is kΩ

3、 问题:An amplifier has a voltage gain of 100 V/V and a current gain of 1000 A/A. The power gain in decibels is dB

4、 问题:An amplifier operating from a single 15-V supply provides a 12-V peak-to-peak sine-wave signal to a 1-kΩ load and draws negligible input current from the signal source. The dc current drawn from the 15-V supply is 8 mA. The power dissipated in the amplifier is mW.

5、 问题:The output voltage of a voltage amplifier has been found to decrease by 20% when a load resistance of 1 kΩ is connected. The value of the amplifier output resistance is Ω

## 2 运算放大器 第2单元测验

1、 问题:The circuit shown in Fig. (a) can be used to implement a transresistance amplifier. Find the value of the input resistance , the transresistance , and the output resistance of the transresistance amplifier. If the signal source shown in Fig. (b) is connected to the input of the transresistance amplifier, find its output voltage. A: B: C: D: 2、 问题:Use the idea presented in the figure below to design a weighted summer that provides Which choice is correct? A: B: C: D: 