posted by Kevin on .
What length of #22 B&S gauge copper wire is needed to make a resistance of 500 ohms?
This is what I came up with but don't think it is correct. looked up diameter for #22 gauge wire = .643 mm and converted to m 6.46 * 10^-4.
Used Eq. A = (pi)(d^2)/4 =>
A = (pi)(6.43 * 10^-4)^2/ = 3.24 * 10^-7 m
Then I used R=(p)l/A and rearranged so now its (R)(A)/p = l
p was given in a chart in my book for copper wire as p = 1.72*10^-8 so here is what I did and the answer I got for l
to me this seems like a very long piece of wire so I think I did something wrong