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" />

已知连续时间系统的系统函数，则其幅频特性响应所属类型为        。http://image.zhihuishu.com/zhs/onlineexam/ueditor/201906/333cbdcdee794d72a5752006c2daabb8.png

某最小相位系统的对数幅频特性曲线如下所示，写出系统的开环传递函数为（ ）。http://image.zhihuishu.com/zhs/onlineexam/ueditor/201906/3f0edd0d4518456895320be18a4e5c9b.png

已知某最小相位系统的开环相频特性为 确定相角裕度为30°时的开环传递函数为（ ）http://image.zhihuishu.com/zhs/onlineexam/ueditor/201906/333ebb35c1be40acaad86070b920d094.png

下列尺寸标注正确的是（ ） A: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201906/79ed6f04ee2f415c917c9f280eccf07e.png"> B: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201906/4677ac7155c849bebe9d2ffd7458f4c4.png"> C: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201906/489ad68ff6294831bc43fa08990b59b7.png"> D: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201906/e829c514224942f1926c1823be08d3e7.png">