How Does a Light Bulb Work?

An incandescent bulb mainly consists of two parts—the bulb and the filament. The bulb is generally made of glass, within which is a vacuum. The filament inside the bulb is where the actual light is produced. It is made of a long and coiled material that is a good conductor of electricity, such as tungsten.

When the electric current flows through the filament, the atoms are agitated, and the electrons within them are excited to higher energy levels as soon as they absorb energy from the flowing current. The time that the electrons remain in this excited state is very small, and when they return to their original energy levels, extra energy is released in the form of photons (small packets of light energy). In this way, the light bulbs glow!