利用电场线巧解静电问题薛三存在学习电场强度时，为了形象地描述电场中各点场强的大小和方向，可以采用画电场线的方法。在电场中画出一系列曲线（或直线），使曲线上每一点的切线都跟该点的场强方向一致，这些曲线就叫做电场线，曲线的疏密程度表示场强的大小。利用电场... Solving Electrostatic Problems Using Electric Field Lines When Xue Xue has learned the electric field strength, in order to visually describe the magnitude and direction of field strength at each point in the electric field, a method of drawing electric field lines can be used. Draw a series of curves (or straight lines) in the electric field, so that the tangent of each point on the curve is consistent with the direction of the field strength. These curves are called electric field lines. The degree of density of the curves indicates the magnitude of the field strength. Use electric field...