A light bulb represents a passive electrical element called a resistor. The reason that lightbulbs are used so extensively to teach elementary electronics is that they allow students to see the power that they are producing. A light bulb is producing power in a number of different ways, but most noteably it is producing power through the heat and light that it is giving off. If it is generating 60W of power a proportional amount is being converted to light. If you look inside the light bulb above you can see the tungsten filament that is producing the light. The reason that it is encased in a glass bulb is so oxygen cannot get to it. If oxygen was around the filament when its at its peak temperature of approximately 2500 degrees celcius, the filament would react with oxygen to oxidize the filament and burn out the bulb.
- Back to PhysicsHelp