![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c24095e409b025db711f14be783a406c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c24095e409b025db711f14be783a406c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c24095e409b025db711f14be783a406c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6f58888df91890a19a1aa7511d19703f.png)
(1)若以任意角度射向磁场的质子都能实现“反射”,求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6f58888df91890a19a1aa7511d19703f.png)
(2)若匀强电场方向竖直向下,场强大小
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/502da6513ca59279d3b932d19903ff45.png)
(3)计算说明如何调控电场,实现质子束从P点进入Ⅱ区发生“全反射”(即质子束全部返回Ⅰ区)。
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/22f513c72c48ed22e0c952e759ce6121.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b5060ad37c403f248c937c1d59af5c71.png)
(1)粒子在第三象限运动时所受洛伦兹力冲量的大小;
(2)矩形磁场区域的最小面积及扇形区域最外侧弧形处的电场强度大小;
(3)半圆形磁场区域的最小半径及粒子从A点飞出到第二次经过x轴的时间。
3 . 如图所示,在xOy平面第二象限内,直线上方有沿y轴正方向的匀强电场,x轴下方有垂直于纸面向里的匀强磁场。现有一质量为m,电荷量为
的带电粒子以速度
从x轴上P点
沿与x轴正向成
的方向射入匀强磁场,经磁场偏转后从x轴上Q点射出,最后粒子恰垂直通过y轴上的N点(图中未画出)。已知
,带电粒子在磁场中运动过程中离x轴的最远距离为b,不计带电粒子的重力。求:
(1)匀强磁场磁感应强度的大小;
(2)N点的y轴坐标。
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9c247de3bfc83aa61bba7634ee443b7f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/12fe32dfbd66709875c5b9f79c9496da.png)
(1)求从M点进入正方体区域的粒子进入时速度的大小;
(2)若该区域内部只有垂直平面MPRG向外的匀强电场,电场强度大小为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3322197ba93dc2de963ef69e173c121b.png)
(3)若该区域内同时存在上述磁场与电场,求所有落到平板上的粒子的落点离
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/12fe32dfbd66709875c5b9f79c9496da.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7ee31829d0d4d5f779a957d7df8058ab.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a6e2e79843faf62dde86bf858d1e0569.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/db2b74d89854116e411c089d053df053.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c24095e409b025db711f14be783a406c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a866194f23f1003d6c3993372dc21720.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bc13a607ac0c7f76d252d7cb1bb040fd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d053b14c8588eee2acbbe44fc37a6886.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d053b14c8588eee2acbbe44fc37a6886.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f6b86c22b670a8e9f3896f9e8883fbbb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/294f5ba74cdf695fc9a8a8e52f421328.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7c22c96b4d06bc3172cbeb08f4e8c4d2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6b1c1f4cfcce790342cdbf02b2d23e9e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/21b25098b4afddf05c8c6d293f2eb20e.png)
(1)带电粒子从
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
(2)匀强电场的场强大小。
6 . 如图所示,在xOy平面第一象限内,直线y=0与直线 y=x之间存在磁感应强度为B,方向垂直纸面向里的匀强磁场,x轴下方有一直线CD与x轴平行且与x轴相距为a,x轴与直线CD之间(包含x轴)存在沿 y轴正方向的匀强电场,在第三象限,直线 CD与直线 EF 之间存在磁感应强度也为B、方向垂直纸面向外的匀强磁场。纸面内有一束宽度为 a 的平行电子束,如图,沿y轴负方向射入第一象限的匀强磁场,各电子的速度随入射位置不同大小各不相等,电子束的左边界与y轴的距离也为a,经第一象限磁场偏转后发现所有电子都可以通过原点并进入 x轴下方的电场,最后所有电子都垂直于 EF 边界离开磁场。其中电子质量为m,电量大小为e,电场强度大小为则下列说法正确的是( )
A.电子进入 x轴上方磁场前的最大速度![]() |
B.电子经过直线CD时的最小速度![]() |
C.速度最小的电子在第三象限磁场中做圆周运动的圆心坐标(![]() ![]() |
D.直线 EF 的方程![]() |
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b97a421b23550ee279df1f392419a347.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b97a421b23550ee279df1f392419a347.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7aeb9a94e392f6759b18abed89aacc5e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/294f5ba74cdf695fc9a8a8e52f421328.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6f58888df91890a19a1aa7511d19703f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6f58888df91890a19a1aa7511d19703f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8ac09dc1ca2cdd7aef28c218763d3e4d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0c88d9142df6ba8e43c1a93bd04a1362.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6670479a0083dd2dfd5ad55b47b1ab6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/635ccd929471d564cc9d2d96266b34d1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
(1)该带电粒子的电性及电荷量大小;
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aa01e2021a91d79149b229ae27f1734c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/87c7eb49a823f757461cd5260757b088.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/65ec432e000cecbd58d96f3889efdba4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bc13a607ac0c7f76d252d7cb1bb040fd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6f58888df91890a19a1aa7511d19703f.png)
(3)若满足(2)条件,带电粒子第二次离开磁场时的位置与A点的距离(结果用根号表示)。
8 . 现代科技中常利用电场和磁场来控制带电粒子的运动。某控制装置如图所示,长方体空间aghd-a′g′h′d′是由边长均为L的三个正方体空间区域Ⅰ(abcd-a′b′c′d′)、区域Ⅱ(befc-b′e′f′c′)、区域Ⅲ(eghf-e′g′h′f′)组合构成,以a点作为坐标原点,以沿着ab方向、aa′方向、ad方向作为x轴、y轴、z轴的正方向,建立三维空间坐标系。区域Ⅰ内充满沿y轴负方向的匀强磁场,磁感应强度大小为(大小未知);区域Ⅱ内充满沿y轴正方向的匀强电场;区域Ⅲ内充满匀强磁场,方向平行于xoy平面且与x轴正方向、y轴负方向均成45°角,磁感应强度大小为
(大小未知),区域Ⅲ的下表面是一个粒子收集板,若粒子打到收集板上将不再射出。现有一质量为m、电荷量为q的带正电粒子从M点
在xoz平面内以速度
沿某一方向进入区域Ⅰ,经过一段时间恰好经过c点,且速度沿x轴正方向,然后进入电场强度为
的区域Ⅱ,粒子重力不计。
(1)求区域Ⅰ内的磁感应强度大小;
(2)求粒子刚进入区域Ⅲ时的坐标及速度大小;
(3)若粒子能够在区域Ⅲ内直接打到粒子收集板上,求的取值范围;
(4)若区域Ⅲ磁感应强度的大小,则粒子从区域Ⅲ返回区域Ⅱ时,在区域Ⅱ内立即撤去原来的匀强电场,同时加上一个沿着y轴正方向的匀强磁场,磁感应强度的大小
,求粒子射出区域Ⅱ时的坐标。
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/70a3dd0be444bb08ff74c4e3e0bef010.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d6c5ec685e8420a8672cefa43e45869.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/58d6961838f6bd0917fe95735d7c53dc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0e48c42c6c44bc2cd4d80b0de64e94a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1792733ec08b4cfd592d4d3abd9f7103.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/70a3dd0be444bb08ff74c4e3e0bef010.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d6c5ec685e8420a8672cefa43e45869.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4c1026c8bd30edecb4c20f9ba74e1fa6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9887d5c789b4a099dc40388b600c2529.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/344ccbf79da6ad7e3709d6fa72efb756.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/541fea8977d62bb3562fc40503ec02fe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/70a3dd0be444bb08ff74c4e3e0bef010.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f271808024917900913a161f44a9a947.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/58077df3e03c8d2a54cc409e366019f2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/97c01fdc7bc471af0b264a04aef0823e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0c88d9142df6ba8e43c1a93bd04a1362.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/43a71fc9c0068109dad1382354570665.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a406570b32dede046e467890780c95b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/18f0281e6bbdbe08beeccb55adf84536.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1bf913efed4da4209c10d14bb3e30b52.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/58077df3e03c8d2a54cc409e366019f2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/44f7616c9ed881b854ad829105de2a3c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0c88d9142df6ba8e43c1a93bd04a1362.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/70a3dd0be444bb08ff74c4e3e0bef010.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d6c5ec685e8420a8672cefa43e45869.png)
(1)匀强磁场I、II的磁感应强度
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/97c01fdc7bc471af0b264a04aef0823e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/43a71fc9c0068109dad1382354570665.png)
(2)从
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d6c5ec685e8420a8672cefa43e45869.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
(3)从
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/70a3dd0be444bb08ff74c4e3e0bef010.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/67229c5c4890e3e1bc89910e881c4cff.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e980bb01962585dfd879f87804f572c9.png)
(1)微粒的比荷
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9da659de03afffb155aaa89e6d1f7e70.png)
(2)d点与O点的距离x;
(3)仅改变磁场强弱而其它条件不变,当磁感应强度Bx大小满足什么条件时,微粒能到达第四象限。
![](https://img.xkw.com/dksih/QBM/editorImg/2024/3/13/99fc7ccc-1769-4f18-aef1-e6864b084066.png?resizew=215)