How Does Temperature Affect the Resistance of a Nichrome Heating Element?

AI Thread Summary
The discussion focuses on calculating the final temperature of a Nichrome heating element in a toaster, given its initial resistance and current values. The resistance at 20 degrees Celsius is 150 ohms, with an initial current of 2 A, which decreases to 1.73 A at the final temperature. Participants emphasize the importance of the temperature coefficient of resistivity to determine how resistance changes with temperature. The resistivity of Nichrome is temperature-dependent, and users are encouraged to reference data sources for accurate values. Understanding these relationships is crucial for solving the problem effectively.
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Homework Statement



A toaster with a Nichrome heating element has a resistance of 150 omega at 20degrees Celsius and an initial current of 2 A. When the heating element reaches its final temperature, the current is 1.73 A. What is the final temperature of the heating element?


Homework Equations



Not sure if they will help but...

(for the equations below i will use p as rho)

R = (p) (L/A)

temperature coefficient of resistivity, alpha = ((p - p0)/p0)/ (T - T0)


The Attempt at a Solution



The only equation relating to the temperature of resistors was the temperature coefficient but I'm not sure how to use it. Thanks for the help!
 
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You need the temperature dependence of the resistivity of nichrome.
Assuming the voltage is the same then from the current you can work out the resistance change and from the temperature coefficent - the temperature change,
 
mgb_phys said:
You need the temperature dependence of the resistivity of nichrome.



I'm not sure what you mean here, could you expand a little please? Thanks.
 
The resistivity of nichrome (like any other metal) depends on it's temperature
You can look up the value in a data book or on the web.
Then you can use this and the resistance change to find the temperature.
 

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