Temperature to raise resistance

AI Thread Summary
To determine the temperature required to increase the resistance of a platinum wire by 3%, the initial resistance and temperature coefficients are essential. The formula R = Ro * [1 + 'a' * (T - To)] is used, where 'a' is the temperature coefficient of platinum. The user notes the lack of an initial resistance value, complicating the calculation. They suggest that if R = 1.03Ro, then Ro can be expressed as R / 1.03, but still face challenges in isolating T without initial resistance. The discussion emphasizes the need for either a known resistance or a method to eliminate variables to solve for the desired temperature.
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Homework Statement


A platinum wire is originally at 15 degree Celcius. Find the required temperature to increase its resistance by 3%.


Homework Equations


R = Ro * [1 + 'a' * (T-To)]
Ro is initial resistance. To is initial temperature.
'Temperature Coefficient' 'a' of platinum at room temperature 20 degree celcius is 3.9 * 10^-3


The Attempt at a Solution


I don't have an initial resistance to start off with. But I do have the initial temperature and the room temperature, To = 15 and T = 20 degree Celcius.

Solving for Temperature T = ('a'To + R/Ro) / 'a'
But I don't have any reference resistance to begin with, how do I solve this?
 
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R = R_o[\alpha (T - T_o) + 1]
R = 1.03R_o
 
xcvxcvvc said:
R = 1.03R_o

Can you show how you got this by eliminating all the other variables? Even from this simplified form, there isn't an initial resistance to begin with. Unless...

R_o = R / 1.03

?
 
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