# Homework Help: Change in the internal energy

1. May 18, 2006

### Amith2006

Sir,
I have a doubt. The internal energy U is a unique function of any state because change in U ___________. I think the answer is internal energy U is a unique function of any state because change in U does not depend upon path.U is a point function. But the given in book is " U depends upon path". Please clear this doubt.

2. May 18, 2006

### siddharth

You're absolutely right.

The change in the internal energy depends only on the inital and final states and does not depend on the path.

Also, the internal energy isn't even a unique function of the state properties. We can never measure the absolute internal energy of a state. We can only measure the changes in internal energy. So the question is doubly wrong.

What book are you using? I'm suprised that there is such an apalling error.

Last edited: May 18, 2006
3. May 18, 2006

### Amith2006

Sir,
I am using a book prescribed for engineering entrance. I feel it may be useful for my GRE Physics exam. Though some of the answers may be wrong, I get so many questions from it. Thank you for your help Sir.