How many filaments are there in a bulb?
A three-way bulb has two filaments of different wattage — typically a 50-watt filament and a 100-watt filament. The filaments are wired to separate circuits, which can be closed initially using a special three-way socket. The switch in the three-way socket lets you choose from three different light levels.
What gasses are in light bulbs?
The most common type of gas mixture found in an incandescent bulb is Argon and Nitrogen. Other gases are also sometimes seen, and they are Helium, Neon, Krypton, and Xenon. The reason these bulbs are filled with these gases has to do with the bulbs’ longevity.