带电粒子在匀强磁场中做圆周运动问题一直是高中物理教学的重难点和命题考查的热点,主要体现在洛伦兹力的应用以及根据圆周运动轨迹中的几何关系进行作图并分析计算.因此,挖掘题干中的几何信息,确定圆周运动的圆心,正确画出圆周运动的轨迹图是解题成败的关键.如何找圆心、画轨迹?通常有以下几何信 The problem of circular motion of charged particles in a uniform magnetic field has been a hot topic in high school physics teaching, which is mainly reflected in the application of Lorentz force and the mapping and calculation based on the geometric relationship in circular motion trajectories. Therefore, it is the key to the success or failure of digging the geometric information in the stem, determining the center of circular motion, and correctly drawing the circular motion map.How to find the center of the circle and draw the trajectory? Usually the following geometric letters