Electric charge and a measure for the quantity of charge Any household electrical appliance – be it a light bulb, a motor, or a television set – has two contacts which have to be plugged in to get the device to operate. This common characteristic, that an electrical apparatus must have two wires connecting it to a source of electricity, gave the rise in the eighteenth century to the idea that when an electrical device is working, something is moving through it. That something is called electric