A light bulb circuit works when the electric current flowing through the light bulb combines with the current flowing in the battery or power source. The filament and wires in the light bulb conduct electricity so that electric current can move through an electric circuit.
An electric circuit enables the movement of electric charges through a closed loop. The presence of an electric current causes free electrons to move around through the wires and filament held by a glass mount in the middle of the light bulb. When an electrical current passes through the light bulb, the electrons produce heat as they move across the wires and filaments. Once heated to a temperature of about 4,000 F (2,200 degrees C), the electrons emit light in the visible spectrum.
The majority of light bulbs use tungsten as the filament material and contain inert gases such as argon. Despite having an extremely high melting temperature, tungsten light bulbs waste electricity when compared to fluorescent lamps and LED light sources. More importantly, LED and fluorescent lamps produce more visible light, which makes them more efficient than traditional tungsten light bulbs. It is for this reason that LED and fluorescent lamps are gaining popularity in several households, says HowStuffWorks.