(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

When a metal rod is heated, not only its resistance but also its length and its cross-sectional area change. The relation R = L/A suggests that all three factors should be taken into account in measuring at various temperatures.

(a) If the temperature changes by 5.0 C°, what percentage changes in R, L, and A occur for a copper conductor? The coefficient of linear expansion is 1.7 10-5/K.

2. Relevant equations

delta L = L initial (delta T) (alpha)

R = density L/A

3. The attempt at a solution

I got the answer to the percentage changes of L and A using the equation

L = L initial (delta T) alpha.

I tried to plug those answers into the equation R = density L/A which gives the answer.5

Unfortunately that answer is wrong and and now I am currently lost.

The percent changes of L and A are:

delta L / L initial = .0085%

delta A / A initial = .017%

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Changes in Resistance due to Temperature

**Physics Forums | Science Articles, Homework Help, Discussion**