Why Does Voltage Versus Energy Exchange in an Electromagnet Show a Linear Trend?

[Da Apprentice]

In order to determine the temperature that an electromagnet reached after a 3 minute period the electromagnet was placed in a constant volume of water. After 3 minutes the change in temperature of the water was measured and from this using the equation Q=mcΔT the energy in joules transferred was calculated. This same process was repeated for the same electromagnet functioning at a different voltage. Graphing the joules exchanged for each experiment against the voltage that the electromagnet was run at produced what appears to be a linear trend.

Why this trend occurred is unknown. It was thought that the trend would be parabolic due to the following;

Joule's First Law: Q=k*I^2*R

Ohms Law: V=I*R (hence I=V/R)

Substitution gives: Q=(k*V^2)/R

I'm not sure if joules law is the correct law to use in this case and so this is most likely why I'm wrong. Can anyone explain why the result would be linear or confirm that it should in fact have been parabolic.

Thanks
Z.C

 

[dazza95]

I have to tell you Da Apprentice:, you have asked a very complicated, multi-part question. It will be a lot of work for us to answer all parts. And our forum rules still apply, you have to do most of the work.

 

[Da Apprentice]

Good one Darren

But seriously can anyone explain why the result would be linear or confirm that it should in fact have been parabolic? Any help would be much appreciated.

Thanks
Z.C

 

[dazza95]

Yes,

Thanks,
DDZ