已知电路中某导体两端电压的变化量△U和通过的电流变化量△I,求该导体的电阻. 电阻是导体本身的一种性质,当导体阻值随温度的变化可忽略时,阻值的大小与该导体两端电压及通过的电流无关.设导体两端电压为U1时,导体中电流为I1,当导体两端电压为U2时,导体中电流为I2.根据欧姆定律, Knowing the change in the voltage across a conductor in a circuit, ΔU, and the amount of change in current passing through it, find the resistance of the conductor. The resistance is a property of the conductor itself. When the resistance of the conductor changes with temperature, it is negligible. The magnitude of the resistance is independent of the voltage across the conductor and the current passing through it. When the voltage across the conductor is U1, the current in the conductor is I1. When the voltage across the conductor is U2, the current in the conductor is I2. According to Ohm’s law,