3.电源电动势为2V,外电路电阻为9 ,测得电源两极间的电压为1.8V,求电源的内电阻?

问题描述:

3.电源电动势为2V,外电路电阻为9 ,测得电源两极间的电压为1.8V,求电源的内电阻?