What are the factors to consider when calculating heat change in a wire loop?

[TheWire247]

I am trying to calculate what the heat change from room temperature is in a wire loop is. I have the power P, the thermal conductivity K , the radius of the wire "a" and the radius of the loop "r". Using Fourier's Law:

P = -KA \frac{\Delta T}{\Delta x}

I am unsure what to use as A and \Delta x. I have the idea that A would be surface area of the wire (4 \pi^{2} a r) and \Delta x would be the just a. Is my thinking right?

 

[T Damen]

A is indeed the surface of the wire. Delta(x) is the distance between the end points. With the radius of the loop you should be able to get delta(x)!

 

[TheWire247]

What do you mean by the end points. Is that the length of the wire?

 

[T Damen]

What do you mean by the end points. Is that the length of the wire?

Yes!

 

[Philip Wood]

The set-up still isn't clear. 'Loop' implies no ends; between what points is there a temperature difference? Without a temperature difference no heat will flow.