如图，输水管经三通管汇流，已知流量Q1=1.5m3/s，Q2=2.6m3/s，过流断面面积A2=0.2m2，断面平均流速v2等于（  ）。http://image.zhihuishu.com/zhs/onlineexam/ueditor/201901/f823e4cbdddd4a0393758dbd91e302c0.png

'已知两直线的方程分别为则（  ）.'https://image.zhihuishu.com/zhs/onlineexam/ueditor/202002/93e0ff51bffb4630aecae06c7585480d.png

变直径管流，细管段断面直径，粗管段断面直径，细管断面雷诺数，粗管断面雷诺数，二者的比例关系是（）。https://image.zhihuishu.com/zhs/onlineexam/ueditor/201909/914a475c62b2488eab641f8b0286ceaa.png

【计算题】有一输水管路,水由输水主管进入两支管。已知:输水主管内径 =200mm,两根支管的流量为 , ,若要求两支管流速均比主管流速大50%,试求: (1)输水主管中的流速 为多少? (2)输水管路中两支管的内径 , 各为多少?

电路如图所示。则u01、u0与 uI的运算关系分别为（ ）、（ ）。 <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201909/418adfb996644706aef30b7d2841ccb9.png" /> A: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201909/ffe4934c2b0748428937c24c7ff16c3b.png" /> B: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201909/1da45f59ab0845f7be8cdc1f80a78caa.png" /> C: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201909/ca685a45d5764329b8551eb6eaeb6a58.png" /> D: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201909/d3f91ade92954e7fbd65a917b04cc13b.png" />