场的立体性注定对学生分析磁场问题的空间想象能力提出了较高的要求。很多学生因不能建立起正确的空间情景 ,或者不能在头脑中保持住正确的空间情景 ,而使问题的分析过程无法继续。如果能够将想象的立体空间情景或已知的立体图景转化成等效平面情景 ,并用平面图展示出来 ,就可 The three-dimensionality of the field is destined to impose higher requirements on students’ spatial imagination ability to analyze magnetic fields. Many students cannot continue the analysis of the problem because they cannot establish the correct spatial scenario or cannot maintain the correct spatial scenario in their minds. If we can transform an imagined three-dimensional space scene or a known three-dimensional scene into an equivalent plane scenario and display it in a floor plan, we can