已知二阶系统的闭环特征方程为
则该系统（）。
A: 不稳定
B: 稳定
则该系统（）。A: 不稳定
B: 稳定
举一反三
- 已知系统的闭环特征根分别为<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202008/5646dab853394a93a36a04ffa8bae221.png" >则该系统（）。 A: 不稳定 B: 稳定
- 函数<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202008/80d8f8a04b644504a6d2e40a33d0eb32.png" >的<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202008/4b92518ac6a14134a358c16900e875c0.png" >阶麦克劳林公式为（） A: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202008/7c2994f9242c43379c6a106d5bd92658.png" >； B: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202008/2145f14f27224b189e702d3390e0a9ba.png" > C: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202008/9ef01b77e76241d9b67b1c7c8cd0eea1.png" >； D: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202008/a0feec59ac5046839ecb5324b27717e0.png" >；
- 一个稳定的线性时不变因果系统的系统函数H（z）的收敛域为（ ）。 A: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202008/a7563f3e60694a96b3b8c4bc57bd2344.png"/> B: <img src="https://image.zhihuishu.com/zhs/aidedteaching/demo/202012/1a83974159a44a68a5e0a60738807710_s1.png" /> C: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202008/66e0e9cf8d0c449e8877f94183e23d89.png"/> D: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202008/2d569f78514c45ce8e308f36af48361c.png"/>
- 两个平行的“无限大”均匀带电平面,其电荷面密度分别为+σ和+2σ,如图所示,则A、B二个区域的电场强度分别为（设水平向右为正方向）：()<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202008/78e393cd69774cd39a6b01baab32e20c.png" > A: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202008/3df0f391d8d744bd98dc43b9717002d4.png" >，<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202008/f87c5783dc7b4f5d98e57cd626b5c95b.png" > B: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202008/9b859042c4284348a9524474ad08eafd.png" >，<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202008/61f01893798a4d17965826ac6341e587.png" > C: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202008/8b8f9aea022c4e6ca7ac133abc21c16a.png" >，<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202008/6fd6170aa1f9495c8e27a96b368c374a.png" > D: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202008/8c0c545adfb54d5d88cfa429928d1302.png" >，<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202008/17de9a98804d4ec09e06a5f8bce2f890.png" >
- 对于下列已达平衡的反应体系，若压缩容器体积，增加体系总压力，平衡正向移动的是（ ）。 A: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202008/326095eaba6d40a3bc4057c25f7eae82.png" /><img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202008/d5573e1b78574bdf970effa5e9509ef4.png" /><img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202008/c8f59ca38f9a41db94d913281b203ada.png" /> B: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202008/41aeceac712749ada229b477082c26aa.png" /> <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202008/d5573e1b78574bdf970effa5e9509ef4.png" /> <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202008/0084729e370b40eab5afb29706560d04.png" /> C: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202008/f92df5cfb06d4322aca5548a0937215a.png" /><img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202008/d5573e1b78574bdf970effa5e9509ef4.png" /><img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202008/8fd7733b85054932be29f9c24c10f538.png" /> D: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202008/bfdf951768ce48989962f5ffbf5b8a97.png" /><img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202008/d5573e1b78574bdf970effa5e9509ef4.png" /><img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202008/6661619fa794442781036239c942bac3.png" />