# Is there a difference between Joule coefficient and Joule-Thomson coefficient?

Is there a difference between the Joule coefficient and the Joule-Thomson coefficient? Also, I am having a hard time understanding what they mean.

• Please consider expanding your question to show that you are contributing original thought and to better illustrate the points of confusion you are having. If you don't, the question is likely to be closed. – Curt F. Feb 11 '15 at 5:55

The Joule coefficient is $(\frac{\partial T}{\partial V})_U$
The Joule-Thompson Coefficient is $(\frac{\partial T}{\partial P})_H$