When the galvanometer reads zero the circuit is in the null-balance position. 當檢流計的讀數為零時,電路處於零平衡位置。
The bar would naturally tend to fall down from the top vertical position, which is a position of unsteady equilibrium. 棒子會有自然的趨勢從最高的豎直位置下落,那是一個不穩定的平衡位置。