用强度为 I ，波长为<img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201804/2656b829b5014d2a9f4038990a94ef61.png" />的 X 射线分别照射锂（ Z = 3）和铁（Z= 26）。若在同一散射角下测得康普顿散射的X射线波长分别为<img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201804/2de5dc6605c04faaabd9c723e2d3cead.png" /><img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201804/96a7971c647c444a88d04338cd33e5fe.png" />，它们对应的强度分别为<img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201804/ccd8dfd4a028462392802a58285139b1.png" />,则（ ）。 A: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201804/9dee8d25d82d4a079c63bce2735e4c00.png" /> B: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201804/4a1eb9d8f57d4a02ab9fac923b14c0a6.png" /> C: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201804/c0b0e797479e4dfa985026ddc4b0513a.png" /> D: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201804/cab491c102954f4088c0b11cbb46fe02.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" />

下面哪张图片是苏州弹词的表演形式？ A: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201804/ea10d729205b47d38658fe913b6a664d.png" /> B: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201804/383680ea91e34e8fa3e77b2a65902fb6.png" /> C: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201804/a194644174af463e99e14749f7e471bd.png" />

如图所示的一细螺绕环，它由表面绝缘的导线在铁环上密绕而成，每厘米绕10匝．当导线中的电流I 为2．0 A时，测得铁环内的磁感应强度的大小 B 为1．0 T，则可求得铁环的相对磁导率<img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201804/c31a3f1826e440f79e7fb4077c8b5656.png" />为（真空磁导率<img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201804/6323a02b04c04433b348982bca792a04.png" />）（ ）<img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201804/21646345be094027b95dfa1075514903.png" /> A: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201804/d61b3d6b1b664ff7a7271955ea8cb90c.png" /> B: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201804/8599397fd0ad4c8a8ce382fc6eda4fd4.png" /> C: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201804/092b8a5debaa47f899b9745dba2a6492.png" /> D: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201804/6647d96f362c41879bd44d76722c7092.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" />