Answer to Question #179793 in Electricity and Magnetism for jabril

Question

A copper wire has a resistance of 15.0 ohms at a temperature of 14 C. After a current passes through the windings, the resistance rose to 12.5 ohms. To what temperature was the wire heated?

Answer 1

Answer

resistance depending of metal on Temperatures

$12.5=15(1+\alpha(T-14) )$

$\alpha=0.00386$

So

$12.5=15(1+0.00386(T-14) ) \\T=0.88C$

So copper wire's temperature is reduced.