Electricity & Magnetism

Electric Flame

An arc of flame marks the path of an electric current. When the button is pressed one side of each pair of electrodes becomes positively charged, and the other side becomes negatively charged. Since opposite charges attract one another, when the electrodes are moved close enough together, the charges will jump across the gap. The glowing light—the visible arc-shaped flame—marks the path that the current takes. The flame is arc-shaped because of the heat it creates. Warm air rises: The heat can be felt above the chamber. The drafts of hot air made by the heat of the arc not only pull the flame upward in the middle, they also make it possible for the flame to jump up from the bottom pair of electrodes to the top pair.