这种点的集合被称为等位面.The set of points is called a level surface.表面本身是一等位面.The surface itself is an equipotential.在等位面与电力线的每个交点, 两者是垂直的.At each crossing of an equipotential and a field line, the two are perpendicular....

“位面”的英语可以翻译为：[计] planes ...