正六边形的尺寸标注正确的是（ ）。
A:
B:
C:
D:
A:
B:
C:
D:
举一反三
- 理想运算放大器的主要特征为 A: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201904/8ec216c374814f48ad60b00627bee3d6.png" /> B: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201904/b36e9dfc39a748b1b652e9b3c1a762ed.png" /> C: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201904/2a93dfdbeb804030ac0da51eed08943e.png" /> D: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201904/a01ee7baba84489f886c43cc5d5c5169.png" />
- 以下属于典型二阶欠阻尼系统的是。（ ） A: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201904/17af3a9e051c466584b8cec615049edd.png" /> B: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201904/6c04a26728e34a868e6efa4d4043d018.png" /> C: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201904/7c45b6ba62234c5e978202c49dd4b455.png" /> D: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201904/8f6cf90035484380beadadba728063ac.png" />
- 负反馈系统的开环传递函数为<img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201904/a7ed7837bacb42a0bc3a3b685f1f59ca.png" />，若要绘制参数<img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201904/20abe260498a4ba4ac78f48ef331ea76.png" />的根轨迹，其等效开环传递函数应该是（ ）。 A: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201904/3fd90fdfd9534f81b6f4b6052f381f27.png" /> B: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201904/c39a9d3fb81b47bead514a12c4ad843d.png" /> C: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201904/916d03716ed144c58426442cc710f9fa.png" /> D: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201904/2f2d63241a46476a9ece1e3ccd8e96e5.png" />
- 零初始条件下系统的微分方程如下0.2<img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201904/a9016a8e310743f2bd58d7f9c8d9d679.png" />，则系统的传递函数为（ ）。 A: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201904/a4bea77a2206422f94416a8b92b1ae1b.png" /> B: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201904/8012e0d7f6374e61aeb25b284d85b182.png" /> C: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201904/9ba5daef946e4f8aa8a46e162da7a01d.png" /> D: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201904/0282eee3912a4d9586d3d28f4fbfc4b1.png" />
- 源电压放大倍数与电压放大倍数的关系是 A: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201904/2f6b445b00df4646b4edacaddd79a7af.png" /> B: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201904/4a0b0c930f934ecdb98e4d8b0c3fe3b4.png" /> C: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201904/d873f32851bf4ff196a2acbb25974b7e.png" /> D: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201904/a5405728c76b40e9ba50a7cf3fd20f7b.png" />