额定电压与额定功率分别是220V,40W和220V,100W的两盏电灯A和B,把它们串联起来接到110V的电压上,它们的实际功率P_物理解答

额定电压与额定功率分别是220V,40W和220V,100W的两盏电灯A和B,把它们串联起来接到110V的电压上,它们的实际功率Pa= Pb=

人气：300 ℃　时间：2019-08-17 23:26:48

解答

RA = U*U / RA = 220*220 / RA = 40 RA = 1210RB = U*U / RB= 220*220 / RB = 100 RA = 484串联后,R = RA+RB = 1694 I = 110/R= 110 /1694 = 0.065Pa = I*I*RA = 0.065*0.065*1210= 5.1 WPb = I*I*RB = 0.065*0.065*...