Re: Filament resistance

["Daniel L. MacIsaac" <Dan.MacIsaac@Nau.Edu>]

> Hello,
>     Recently there was mention of the length of the standard household
> bulb's filament.  What is the diameter of this wire?
>
> Tom McCarthy

> From Cutnell & Johnson PHYSICS 4th Ed. NY: Wiley p.618

Q20.12:  The filament in an incandescent light bulb is made from tungsten.  The
radius of the tungsten wire is 0.045 mm...

Soln manual suggests a 150W bulb has a 11m long filament.  If the above radius
is correct, I concur.

/rho_{tungsten} = 5.6 x 10^{-8} ohm * m


Dan M

Dan MacIsaac, Assistant Professor of Physics and Astronomy, Northern AZ Univ
danmac@nau.edu  http://www.phy.nau.edu/~danmac/homepage.html