“金属导体中的电流是怎样形成、怎样流动的？”“电流为什么流得那么快？”有的同学认为，电流既然是电荷定向移动形成的，就应与水的流动差不多；电源就是电流之“源”，只要一台上开关，电荷就会从电源正极源源不断地流向电源的负极，因此图1中的甲灯比乙句光亮．其实，这种 “How does the current in the metal conductor form and flow?” “Why does the current flow so fast?” Some students believe that since the current is formed by the charge directional movement, it should be similar to the flow of water; the power supply is the current. “Source”, as long as a switch, the charge will continue to flow from the positive source of the power supply to the negative pole of the power supply, so Figure 1 in the nail light is brighter than the B sentence. In fact, this kind of