如图所示,真空室中y轴右侧存在连续排列的n个圆形边界磁场,圆心均在x轴上,相邻两个圆相切,半径均为R,磁感应强度均为B。其中第1,3,5
![](https://math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmtext%3E%E2%8B%85%3C%2Fmtext%3E%3Cmtext%3E%E2%8B%85%3C%2Fmtext%3E%3Cmtext%3E%E2%8B%85%3C%2Fmtext%3E%3C%2Fmath%3E)
个圆形边界的磁场方向垂直于纸面向里,第2,4,6
![](https://math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmtext%3E%E2%8B%85%3C%2Fmtext%3E%3Cmtext%3E%E2%8B%85%3C%2Fmtext%3E%3Cmtext%3E%E2%8B%85%3C%2Fmtext%3E%3C%2Fmath%3E)
个圆形边界的磁场方向垂直于纸面向外,第n个磁场右侧有一个粒子接收屏与x轴垂直,并与第n个磁场相切,切点为M,第n个磁场方向图中未画出。在磁场上方和下方分别有一条虚线与磁场相切,上方虚线上方有一向下的范围无限大的匀强电场,下方虚线下方有一向上的范围无限大的匀强电场,场强大小均为E。现将一群质量均为m、电荷量均为
![](https://math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmo%3E%2B%3C%2Fmo%3E%3Cmi%3Eq%3C%2Fmi%3E%3Cmrow%3E%3Cmo%3E%28%3C%2Fmo%3E%3Cmrow%3E%3Cmi%3Eq%3C%2Fmi%3E%3Cmo%3E%26gt%3B%3C%2Fmo%3E%3Cmn%3E0%3C%2Fmn%3E%3C%2Fmrow%3E%3Cmo%3E%29%3C%2Fmo%3E%3C%2Fmrow%3E%3C%2Fmath%3E)
的带电粒子从坐标原点O点向第一、四象限各个方向发射(不考虑平行于y轴方向发射的粒子),射出速度均为
![](https://math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmi%3Ev%3C%2Fmi%3E%3Cmo%3E%3D%3C%2Fmo%3E%3Cmfrac%3E%3Cmrow%3E%3Cmi%3Eq%3C%2Fmi%3E%3Cmi%3EB%3C%2Fmi%3E%3Cmi%3ER%3C%2Fmi%3E%3C%2Fmrow%3E%3Cmrow%3E%3Cmi%3Em%3C%2Fmi%3E%3C%2Fmrow%3E%3C%2Fmfrac%3E%3C%2Fmath%3E)
。不计粒子重力,则下列说法正确的是( )
![](http://tikupic.21cnjy.com/2024/06/02/39/53/39536be6e700aa53f2c09f1789e8b001.png)