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在一本初中物理同步练习册上有这样一道乙两处分别接有电源和电灯,根据图中标出的电流方向,可判断通过灯L2的电流方向是()A.一定由下向上流动。B.一定由上向下流动。C.向上、向下均有可能。D.因电源位置不确定而无法判断。分析与解设接入的电灯为L,有如下两种情况:图2(所1)示甲
In a junior high school physics synchronization exercise book, there are two such power supplies and electric lights in B. According to the direction of the current marked in the figure, it can be determined that the direction of the current passing through the lamp L2 is () A. It must flow from bottom to top. B. Must flow from top to bottom. C. Both up and down are possible. D. It cannot be judged because the power supply position is uncertain. Analyze and solve the access lamp is L, there are the following two situations: Figure 2 (the 1)