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Q & A: Why does the bulb get hot & the wire stay cool?

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Most recent answer: 04/06/2011
Q:
Explain why the filament of a light bulb connected to a battery receives much more power than the wire connecting the bulb and the battery
- Bob Saget (age 18)
galveston, tx
A:
It's all a matter of relative resistance.  The amount of current flowing through the wire and the bulb is the same.  The power dissipation in a circuit element is proportional to I2R where I is the current and R is the resistance of the element.  Since the resistance of the bulb is much more than the resistance of the wire, the bulb gets hot and the wire stays cool.

LeeH

(published on 04/06/2011)

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