，系统稳定时
的取值范围是（ ）。A: K1＞0
B: 0＜K1＜34.6
C: K1＜34.6
D: K1＞34.6
举一反三
- 已知某系统的劳思表如下所示[img=266x138]17d624db043fa92.png[/img]，系统稳定时[img=28x40]17d624db10fb83c.png[/img]的取值范围是（ ）。 A: K1＞0 B: 0＜K1＜34.6 C: K1＜34.6 D: K1＞34.6
- 开环系统频率特性<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202108/d87c0f560f1542028a3602b52456fae0.png" />，当<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202108/c0f50539680f40a784c2a0d803f0f5d7.png" />时，其频率特性相角<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202108/ff41a81bec7c421c8178de199c438e05.png" />（ ）。 A: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202108/589b5e2ab46b459882a2824ff9567c36.png" /> B: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202108/370b677492de485ca61114324b5d00fe.png" /> C: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202108/95723a2a938f4944a98b18d89f607986.png" /> D: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202108/c08161009369424f9a3510d7c77d9943.png" />
- 下列方程为伯努利方程的是（ ）。 A: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202108/0622f56257874ab19e680d587fd8a4fc.png"> B: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202108/5ce3fc785b724e3da7d07b8d6a0ecaf3.png"> C: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202108/ab3de1c35e9e419fa301a33bddd5ee0c.png">+<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202108/2c226f2daecf40448b08c3b26a4db60e.png"> D: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202108/88be95dd74814341a1894f32f073b9ec.png"><img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202108/00fbcbc7c3574f94934fa3adc8843ccf.png">
- 已知f(k)的z变换<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202105/fcb29424b0f74f9d8bf5e13ec738f383.png" />，F(z)的收敛域为下面哪一项时，f(k)为因果序列 ( )。 A: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202105/a75ad7c5eb8849f6a24916fc871c1739.png" /> B: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202105/3e62806a63e74e78bb29212d2a5bef0a.png" /> C: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202105/25250b041bec4d5093675240862554e4.png" /> D: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202105/2eae229138be4af5a084d0996e2d57d2.png" />
- 欲使JK触发器按Qn+1=1工作，可使JK触发器的输入端（ ）。 A: J=<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202012/7f3d0fb0ee6647b2acae2836c7296ac9.png" />,K=0 B: J=K=0 C: J=K=<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202012/7f3d0fb0ee6647b2acae2836c7296ac9.png" /> D: J=1,K=0 E: J=K=1
内容
- 0
直线<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202108/64709df03a7b45ebbc6d752183b8f22e.png" />与直线<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202108/5ca5aa44859c42ddaa3207626d2b9537.png" />的公垂线方程为（ ） A: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202108/a4c463fa2c3f49df9d7f2bb2e9fc4030.png" /> B: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202108/627b64a33e944efcba416aea0f40dc76.png" /> C: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202108/966e8a14e6754060b800dff88721784a.png" /> D: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202108/f8f41491de204a9eb3fb306208c3b08a.png" />
- 1
下列性能指标中的（ ）为系统的稳态指标。 A: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202108/14f12f89af1147c1acaedbcb38294237.png" /> B: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202108/e89d7e9ba7c14b7db9f8c58a52e89317.png" /> C: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202108/c3c17142d0a04a7b84588ca8b4730f32.png" /> D: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202108/aabfc0e7269843f9bfed3b6e3cd0421b.png" />
- 2
因果序列f (k)的z变换<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202106/9fa9430ba33a4810b132471715422bfc.png" />，则f(0)的值为( ) A: 0.5 B: 1 C: 3 D: 不存在
- 3
以下哪种图形表示选择结构（ ） A: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202108/00e6d9ad2328497da022b3b20603d7f8.png"> B: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202108/c6055ccfaafa4eafa3451f45a78535ae.png"> C: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202108/b9cd7369284644b29d3499a3025d9cb3.png"> D: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202108/8129afad6fcf46cb8c2d79c7e744809e.png">
- 4
球面的中心在点C(1,3,-1)，而且球面通过坐标原点，则该球面的方程为（ ） A: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202108/ce53ea6364164afcafb95b6de33ddd99.png" /> B: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202108/df6006b5e38647b4aac2a31356bdee1c.png" /> C: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202108/5367c45bef194132a343005dcfa1e262.png" /> D: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202108/34c90bdb258b4636bd6986839e67361f.png" />