Nichrome Resistor and Copper wire

AI Thread Summary
A 10-ohm Nichrome resistor is connected to copper leads, which add an additional resistance of 0.03 ohms. The discussion focuses on determining the temperature change required for the Nichrome resistance to equal that of the copper leads. The relevant equations involve the temperature coefficients of resistance for both materials. An initial attempt calculated the temperature change as 30.6°C, but this was identified as incorrect due to an algebra error. Participants encourage re-evaluation of the calculations to find the correct temperature change.
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Homework Statement


A 10 ohms Nichrome resistor is wired into an electronic circuit using copper leads (wires) of diameter 0.6 mm with a total length of 50 cm. The additional resistance is due to the copper leads is 0.03 ohms.

What change in temperature would produce a change in resistance of the Nichrome-wire equal to the resistance of the copper leads?

Homework Equations



RCu = 0.03[1 + aCu(tC – 20)]= change in Rw = 10aw(tC – 20); solve for tC
aCu at 20 degree C= 3.9 x 10^-3
aw at 20 degree C = 4.3 x 10^-3

The Attempt at a Solution



0.03[1 + aCu(tC – 20)] = 10aw(tC – 20)
I solved for tc and got 30.6 C but it is not the right answer so please help.
 
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Welcome to PF :smile:

30.6 C does not solve the last equation you wrote. There must have been some algebra error made after that.

You are on the right track, try again. You can check your answer by substituting it into your equation,
0.03[1 + aCu(tC – 20)] = 10aw(tC – 20)
 
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