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

Find the resistance of a1.4 mlength of copper wire with diameter of5*10^-3 m.

2. Relevant equations

R = p(L/A) where p = resistivity of copper, L = length, A = area

3. The attempt at a solution

The resistivity of copper is (1.69 * 10^-8). Radius is d/2 (5*10^-3) / (2) =(2.5*10^-3)

With the radius, the Area A = pi(2.5*10^-3)^2 =(1.96*10^-5).

Plugging it into the equation R = p(L/A)

(1.69*10^-8)*(1.4) / (1.96*10^-5) =(1.2*10^-3) Ohm

There were two similar questions like this where the same approach yield me the correct answer. Somehow this answer I get is incorrect. What am I doing wrong?

On a side note, how many questions may I post?

**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!

# Homework Help: Find resistance of copper wire.

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