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Homework Help: Current in a hollowed nichrome wire

  1. Mar 3, 2012 #1
    1. The problem statement, all variables and given/known data

    A 10.0 cm long hollow nichrome tube of inner diameter 2.20 mm , outer diameter 5.10 mm is connected to a 2.50 V battery. What is the current in the tube?

    2. Relevant equations
    R = p*(L/A);p = resistivity of nichrome (1.5E-6), L = length of wire, A = Surface area of cross section

    3. The attempt at a solution
    V = I*R → V/R = I; V = 2.5V
    R = p*(.1cm)/(π([5.1/2]/1000))2)-π((1.1/1000)2))

    I = 2.5/R; Isn't correct
  2. jcsd
  3. Mar 3, 2012 #2
    Looks good to me, you must have done some calculations wrong... If you used wolframalpha or similar, your brackets are wrong so that might have messed it up...

    I got R=0.00902 ohms, I=277 A
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