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!

Calculate the resistance of iron if

  1. May 9, 2008 #1
    1. The problem statement, all variables and given/known data
    A rectangle bar of iron is [tex]2cm[/tex] by [tex]2cm[/tex] in cross section. Calculate its resistance if the resistivity of iron is [tex]11 \times 10^{-8}\Omega{m}[/tex].

    2. Relevant equations

    [tex]R = \frac{Pl}{A}[/tex]

    3. The attempt at a solution

    [tex]R = \frac{Pl}{A}[/tex]

    [tex]A = 2 \times 2 \times 10^-4 = 4 \times 10^{-4}m[/tex]
    [tex]P = 11 \times 10^{-8}\Omega{m}[/tex]

    How is it possible to find the resistance If I don't have the length?
  2. jcsd
  3. May 9, 2008 #2


    User Avatar
    Homework Helper
    Gold Member

    It isn't.

    Maybe they are looking for the resistance per unit length:

Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Similar Discussions: Calculate the resistance of iron if
  1. Calculating Resistance (Replies: 1)

  2. Calculating resistance (Replies: 1)

  3. Calculating Resistance (Replies: 5)