Incandescent light bulbs and Ohm's law

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roberto
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Location: Italy

Re: Incandescent light bulbs and Ohm's law

Post by roberto »

JMFahey wrote:Thanks Roberto :)

From one table in your link, Tungsten at 2700 degrees Kelvin (about what lamp filaments rise to) resistance is over 20X that of ambient temperature.
Not exactly. That's what the table says, but it's wrong.
The real ratio is around 14x (look at the values shown).

Looking at what xtian found, this ratio is confirmed:
26 Ohm (@ 300 K) x 14 (R @ 2700 K / R @ 300 K) = 364 Ohm (@ 2700 K)
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JMFahey
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Location: Buenos Aires - Argentina

Re: Incandescent light bulbs and Ohm's law

Post by JMFahey »

roberto wrote:
JMFahey wrote:Thanks Roberto :)

From one table in your link, Tungsten at 2700 degrees Kelvin (about what lamp filaments rise to) resistance is over 20X that of ambient temperature.
Not exactly. That's what the table says, but it's wrong.

Ok, then I un-thank you because you posted the wrong table.

Is that ok with you now?
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roberto
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Location: Italy

Re: Incandescent light bulbs and Ohm's law

Post by roberto »

:lol: :lol: :lol: :lol: totally ok! :lol: :lol: :lol:

All those infos are good, except the dumb who calculated the ratios.
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