设A为阵，其秩为r，则当r=m时，下列结论错误的是（ ）.http://image.zhihuishu.com/zhs/onlineexam/ueditor/201804/8b43ab9dd5db4034a51ff166890bfd98.png
举一反三
- 设A为阵，其秩为r，则当时，下列结论错误的是（ ）.http://image.zhihuishu.com/zhs/onlineexam/ueditor/201804/951786de33bc478ca2bdf63278a6e5a9.png
- 设某微观粒子的相对论动量是它非相对论动量的<img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201804/f04bc52895444aa9bf3ce69591507d4b.png" />倍，则其运动速度的大小为：（ c 表示真空中的光速）（ ）。 A: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201804/39876687533246689c09bf2af4be1fe2.png" /> B: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201804/dd046c8367ec4635b34aaad5ceffe48b.png" /> C: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201804/99f25f4748cf434c96c5fa7552098ff5.png" /> D: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201804/85033bc491434663a83ffea2611f0c2b.png" />
- 矩阵A适合条件（ ）时，它的秩为.http://image.zhihuishu.com/zhs/onlineexam/ueditor/201804/b86f239936464d0ca8b1b6a23bb36044.png
- 无限长直导线在P处弯成半径为 R 的圆，当通以电流I时，则在圆心O点的磁感强度大小等于（ ）。<img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201804/ea9d82a600684de2a916e5c304869893.png" /> A: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201804/ba82b51586c84ba098c3a6464b629ffa.png" /> B: 0 C: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201804/5ed485ce1868458ca1d09cb5e134c4d0.png" /> D: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201804/07acf7ef8e7f4393864785943a134038.png" />
- 设A为矩阵，且A的行向量组的秩为3，则方程组AX=b（ ）.http://image.zhihuishu.com/zhs/onlineexam/ueditor/201804/bd3d4159077049b3893b52f2e7d10ec9.png