如图示并联管路，已知各支路的沿程阻力系数之比为<img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201909/6e209020d20f4543823ce6516ae8ca06.png" />，管长之比为<img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201909/50814fe028094040bc955d8e1542b6d2.png" />，且<img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201909/40b4c6a9565b483590c5c7d607e7ed66.png" />，则两支管的流量之比<img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201909/1055534bfce6426a94682ba086a5b17e.png" />=（）。<img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201909/77815369f5cd41f3a2e68b9524b454c5.png" /> A: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201909/0cd231eebe45465f941a0f614743e6d2.png" /> B: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201909/7555afa5223e40bf89ca575cf7b52754.png" /> C: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201909/1b06cd474b844644a6d97ad87d208e94.png" /> D: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201909/d0b2bca045414236a7d1c9925a9264f2.png" />

相对密度为0.75的汽油，运动粘性系数，则其动力粘性系数μ的大小和量纲分别为（）。https://image.zhihuishu.com/zhs/onlineexam/ueditor/201909/4af7c6ee8b804636be2277b3b2a748dd.png

在定温边界条件下，稳态、无内热源、导热系数为<img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201909/bf35cea9e03449f0b64673e21dbdde56.png" />、内外径分别为<img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201909/3323de11627a4f51bc7b1fff540dcfef.png" />和<img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201909/675dd37c97db44a7a723838858eab505.png" />、长度为l的单层圆筒壁的导热热阻为（）。 A: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201909/892cb3300ea148d994377392a697acb0.png" /> B: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201909/7003425fa14a44d5aadbb9040240edca.png" /> C: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201909/040ff55c3a244877a0b06faf6042f47a.png" /> D: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201909/b5d2a5ed4d644ae6b2dab35d2ed8f3e5.png" />

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" />

如右图所示拉杆头的挤压面积为( )。<img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201909/7ddd21a3a4e849f68c4d176b971c7c55.png" /> A: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201909/df97de243a424ac58b1dc7cb70374683.png" /> B: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201909/eab41cb13f55410ea57bc67fbf155a7b.png" /> C: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201909/8c54a383f7e8426eb0f0f7c435a433ba.png" /> D: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201909/9120d45143384f29aef7b86ea444f7f3.png" />