Does filament size or resistance affect the brightness of a lightbulb?

AI Thread Summary
The discussion centers on the relationship between filament size, resistance, and light bulb brightness. It is established that a filament with lower resistance allows more current to flow, resulting in increased brightness due to higher power output, as power is calculated by the formula P=V*I. While smaller filaments typically have higher resistance, which can lead to less brightness, the overall effect depends on the voltage supplied. A larger filament can indeed produce a brighter light if it allows for more current without exceeding the voltage limit. Understanding resistive heating is crucial to grasping these concepts fully.
southern69
Messages
2
Reaction score
0
Does anyone have a clear understanding on the relationship between the filament size of a lightbulb and the wattage? I was under the impression that resistance causes the filament to heat up and glow, so the more resistance the brighter the light bulb. A filament with more resistance, then, would have to be smaller. However I have read that a larger filament causes a bulb to grow brighter. Is this true, and why?
Thanks
 
Physics news on Phys.org
It is true, because the wall is in essence a constant voltage source. Given a constant voltage and a purely resistive load (a decent approximation), a filament with half the resistance will allow twice the current through. Because power is V*I, for a constant V and twice the I (current), you will have twice the power.
 
Thanks. But are you saying that more current causes the filament to glow brighter? If this is true could you please try and explain it to me. (sorry)
 
google "resistive heating".
 
Thread 'Motional EMF in Faraday disc, co-rotating magnet axial mean flux'
So here is the motional EMF formula. Now I understand the standard Faraday paradox that an axis symmetric field source (like a speaker motor ring magnet) has a magnetic field that is frame invariant under rotation around axis of symmetry. The field is static whether you rotate the magnet or not. So far so good. What puzzles me is this , there is a term average magnetic flux or "azimuthal mean" , this term describes the average magnetic field through the area swept by the rotating Faraday...

Similar threads

Replies
3
Views
3K
Replies
14
Views
5K
Replies
57
Views
11K
Replies
5
Views
2K
Replies
2
Views
2K
Replies
13
Views
3K
Back
Top