Total Resistance of Parallel Wires: Copper & Aluminum

AI Thread Summary
To find the total resistance of two parallel wires made of copper and aluminum, one must use the formula 1/Rt = 1/Ra + 1/Rc, where R is calculated using resistivity, length, and cross-sectional area. The resistivity values for copper and aluminum need to be adjusted for temperature, as they vary with changes in temperature, typically provided at 25°C. The coefficient of temperature for each material must be incorporated into the calculations to account for resistance changes at 105°C and -40°C. Understanding how to apply these temperature adjustments is crucial for accurate resistance calculations. This approach ensures the total resistance is correctly determined across varying temperatures.
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Homework Statement



Two 1275m long wires are connected in parallel. One conductor is copper at 1.11mm in diameter and the other is aluminum at 2.23 mm in diameter. Find the total resistance of wires at 25 C, at 105 C, and minus 40 C.


Homework Equations



1/Rt=1/Ra+1/Rc
R=resistivity*L/A

The Attempt at a Solution



I thought I would just look up the resistivity and plug into the equation above...but then how do I incorporate temperature?
 
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The resistivity listed will be at some temperature, typically 25C (room temp.). There will also be a coefficient of temperature, where the resistivity increases with temperature. You will need to find that for each material, and incorporate it into your calculations.
 
O ok thank you. That was not in my notes!
 
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