虽然两等量同种点电荷在空间的场强分布比较复图 1杂 ,但仍有其规律性 .为研究方便 ,设它们各带同种正电量Ｑ ,如图 1所示 .图中ａ、ｂ两点在两点电荷 +Ｑ的连线上关于中点Ｏ对称 ,ｃ、ｄ两点在连线的中垂线上关于Ｏ点对称 .1　电场强度的对称性设两点电荷间距为 2Ｌ ,ａｏ =ｂ Although the distribution of the field intensities of two equal quantities of the same kind of point charges in space is more complex than that of Fig. 1, it still has its regularity. For the sake of convenient research, let them be assumed to have the same kind of positive electric quantity Q, as shown in Fig. 1. a The two points on the two charges +Q are symmetrical about the midpoint O, and the two points c and d are symmetrical about the point O on the perpendicular line of the connection. 1 The symmetry of the electric field strength sets the two-point charge spacing to 2L ,ao =b