一个“6V 3W”的灯泡接在9V的电压下,要使他正常发光,应接入阻值多大的电阻?（三种解法）若不接电阻,灯泡实际功率多大?
人气：113 ℃ 时间：2019-08-18 08:43:41
解答
首先不接电阻将超载工作,影响灯泡寿命；灯泡额定电流为0.5A,额定电阻为12欧,实际功率为9*9/12=6.75W；1、分压法：串联电阻分压3V,则灯泡正常工作,所以串联电阻为3/0.5=6欧2、分流法：先并联12欧电阻,则总电流为1A,需...
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