大象传媒

A look at how three different voltages affect the brightness of a board of lightbulbs. First, the lightbulbs are lit using a single battery. The current and voltage are too small to light the bulbs. A larger 12V battery is used in the second attempt. The bulbs do light up, but the light is dim. Finally, the switch is connected to 240V from the mains and the bulbs are brightly lit.