“一对平衡力”的说法欠妥当

The Statement about a Pair of Equilibrating Force is Inappropriate

通过对通电线圈在均匀磁场中的受力分析,进一步明确一对平衡力必须大小相等,方向相反,作用在同一条直线上的力,同时二者还必须作用在同一个物体上.

After analysis of the force acting on the rectangular coil in the uniform magnetic field on the basis of Ampere law, It indicates further that the pair of equilibrating force must be al- ways equal , be directed to contrary parts, and be always opposed an equal reaction , At the same time, they must act on the same object.