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!

Resistance and temp co-efficient?

  1. Feb 25, 2010 #1
    1. The problem statement, all variables and given/known data

    A conductor has cross-section of 10 cm2 and specific resistance of 7.5 ohm cm at 0 degree C
    what will be its resistance in ohm per/kilometer when the temperature is 40 degree C ?
    take temperature co-efficient of the material is 0.005 / degree C

    i cant find the solution of it. please give me solution if you can
    please help me

    2. Relevant equations
    Resistance of a wire in Ω
    R = ρL/A
    ρ is resistivity of the material in Ω-cm
    L is length in cm
    A is cross-sectional area in cm²

    3. The attempt at a solution

    R = (7.5 Ω-cm)(L) / 10 cm²
    R/L = 0.75 Ω/cm

    R/L = 0.75 Ω/cm x 100000 cm/km = 75000 Ω/km

    R/L = 75000 Ω/km x [1+ (0.005/C)*40C]
    R/L = 90000 Ω/km
  2. jcsd
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Can you offer guidance or do you also need help?
Draft saved Draft deleted