‌有一长直螺线管通有电流，使管内形成均匀磁场，一电子初速度<img src="http://jgxm-question.oss-cn-beijing.aliyuncs.com/psst/files/35323fa702b349de83a6de936a47bae5.png?x-oss-process=image/sharpen,200"/>沿与管轴夹角为<img src="http://jgxm-question.oss-cn-beijing.aliyuncs.com/psst/files/4ce3f49879fd4a459bfab7c6bfd97d94.png?x-oss-process=image/sharpen,200"/>射入管内，则电子在管内将会‏