# Nichrome wire resistance problem

## Homework Statement

Build a heater that runs on 120vac no more than 10 amps. How many watts, 1mm nichrome wire, how long will it have to be at 20deg C. What will the resistance be at 1200deg F. What is the new power at the new resistance.

## Homework Equations

R=V/I P=E/I R=L/A

P(T)=p0(1+a(t-t0)

Nichrome resistance 100e^-8 at 20 deg C Temp coefficient .0004

## The Attempt at a Solution

I have the wattage for the original, I have the resistance at 1200deg F for 1 meter of wire. I just can not seem to get the right number for the wire length at 20deg C I keep coming up with like 15mm long but it is not right, when you use that length value with the resistance for 1200deg it is soooo far off.

I also tried 1*10^6/1=12/x to find the length and that does not work either and I do not have the wire area if I do it that way. I have gotten myself sooo confused trying to figure out this one part!!!!

Delphi51
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Nichrome resistance 100e^-8 at 20 deg C Temp coefficient .0004