Brightness of lightbulb concept questions

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SUMMARY

The brightness of a lightbulb is directly proportional to the current flowing through it, as established by the equation P = I²R, where P represents power, I is current, and R is resistance. Increasing resistance does not lead to increased brightness because it results in a decrease in current, as described by Ohm's Law (V = IR). Therefore, for a lightbulb to achieve greater brightness, the current must be increased while keeping resistance constant. This relationship highlights the importance of understanding electrical principles in relation to lightbulb performance.

PREREQUISITES
  • Understanding of Ohm's Law (V = IR)
  • Familiarity with the power equation (P = I²R)
  • Basic knowledge of electrical resistance and current
  • Concept of blackbody radiation in relation to heated filaments
NEXT STEPS
  • Research the relationship between current and brightness in incandescent lightbulbs
  • Explore the effects of varying resistance on electrical circuits
  • Study blackbody radiation and its implications for lightbulb design
  • Investigate alternative light sources and their efficiency compared to traditional bulbs
USEFUL FOR

Students of physics, electrical engineers, and anyone interested in the principles of lighting technology and electrical circuits.

jakeddong
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So I googled and found out that brightness of a lightbulb is directly related to current, but for some reason it doesn't match the concept I have in my head.

I know that a lightbulb gets brighter as it gets hotter (like any kind of metal)
So for a lightbulb to get brighter, it needs more energy(for heating)
However this energy comes from the loss of kinetic energy of electrons as they pass through the resistors.
So if you increase the resistance, your lightbulb should get hotter and brighter because electrons lose more kinetic energy at higher resistance.
But according to the formula V=IR, if you increase resistance, the current decreases, which doesn't fit with what I found through google.

Could you tell me what is wrong in my reasoning?
 
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It is true that increasing the resistance to current would increase the brightness of the filament glow as it undergoes blackbody radiation. Yet the heat generated from the release of electron kinetic energy would be tremendous and instantly snuff out the part where it is connected. The reason why current would drop was because it did not even travel through the conductor due to resistance.

The reason that the brightness would increase with current comes from the equation

P= I^2*R
making P proportional to I if R constant

as long as your resistance remains constant, the determinant factor would be current.

That's what I have in mind though
 

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