1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Diameter and resistance

  1. Feb 14, 2009 #1
    1. The problem statement, all variables and given/known data

    If 46 m of nichrome wire is to have a resistance of 12.0 Ω at 20°C, what diameter wire should be used?

    2. Relevant equations


    3. The attempt at a solution

    I tried and I got 2.1. The [tex]\rho[/tex] of nichrome is 108e-8
  2. jcsd
  3. Feb 14, 2009 #2
    First solve for the variable you are looking for and put it on one side. Keep your knowns on the other side. Remember that A stands for area, and area is related to wire diameter.

    I am online for a bit, so give it a go. DON'T FORGET YOU UNITS!
  4. Feb 14, 2009 #3
    ok yeah i got 2.3 mm. after i figured out A. I figured out diameter doing A=1/4pi(dsquared)
  5. Feb 14, 2009 #4
    ok i got it right. thanks!
  6. Feb 14, 2009 #5
    Good for you!
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook