首先看下面例题：一个带正电的电荷在垂直纸面向里的匀图１强磁场中，仅受洛仑兹力作用做匀速圆周运动（逆时针方向），现在使磁感强度随时间均匀增加，设电荷运动中的半径不变，则电荷运动的动能将如何变化？通过做题发现，许多学生对该题束手无策，多数学生认为，尽管磁... First look at the following example: a positively charged charge in the vertical paper surface in the uniform Figure 1 strong magnetic field, only by the Lorentz force to do a uniform circular motion (counterclockwise), now makes the intensity of magnetic induction with time evenly increased Given that the radius of charge motion is constant, how does the kinetic energy of charge motion change? Through the discovery of the problem, many students do nothing about the problem, most students believe that despite the magnetic ...