Homework Help: Magnetic field and its energy?

1. Sep 28, 2007

pivoxa15

1. The problem statement, all variables and given/known data
If a magnetic field has length 1m and strength 1T. What is its energy contained in it?

3. The attempt at a solution
I have no idea as I only know how to calculate energy from a volume basis.

2. Sep 29, 2007

chaoseverlasting

$$F=\frac{-dU}{dx}$$, If you solve for U, you get your general expression and plug in the values there.

3. Sep 29, 2007

Gokul43201

Staff Emeritus
This question looks nonsensical. Did you write it down exactly as it was given to you? Where is this from?

4. Sep 29, 2007

pivoxa15

The question was about the magnetic prominence which is a magnetic loop. I just simplified the data but its about a magnetic loop and finding how much energy it can contain.