交变电流的有效值是描述交变电流的一个重要物理量,其定义是:“让交变电流和恒定电流分别通过大小相同的电阻,如果在交流的一个周期内它们产生的热量相等,而这个恒定电流是I、电压是U,我们就把I、U叫做这个交流的有效值.”从定义我们不难看 The effective value of the alternating current is an important physical quantity that describes the alternating current. It is defined as: “Let the alternating current and the constant current pass through the same resistance respectively, and if they generate the same heat during one cycle of AC, The constant current is I, the voltage is U, and we call I, U the effective value of this exchange. ”" From the definition we are not hard to see