# Magnetic Field due to a current loop

1. Mar 3, 2008

### snoweangel27

[SOLVED] Magnetic Field due to a current loop

1. The problem statement, all variables and given/known data

A single loop of wire of radius 3 cm carries a current of 2.6 A. What is the magnitude of B on the axis of the loop at 2 cm?

2. Relevant equations

B=$$\mu$$/(4$$\pi$$) * 2$$\pi$$(R^2)*I/(z^2+R^2)^(3/2)

3. The attempt at a solution
I = 2.6 A
R = .03 m
z = .02m

I calculate .000031 T
It should just be a simple matter of plugging in numbers, but every time I use this equation it ends up being wrong. If anyone could tell me what I might be doing wrong it would be greatly appreciated.

2. Mar 3, 2008

### Staff: Mentor

Looks OK to me. Why do you think it's wrong?

3. Mar 3, 2008

### snoweangel27

It is computerized homework, so when I put in the answer that I calculated it keeps telling me that it is wrong. I have done the same thing with multiple different distances, and they all come up wrong, so I believe that it is something that I am doing, I am just not sure what

4. Mar 3, 2008

### Staff: Mentor

Those online systems can be flaky. I don't think you're doing anything wrong. Your equation is correct and your answer is correct.

Things to check: Are you sure they want the answer in Teslas? How many sig figs does the system like?

5. Mar 3, 2008

### snoweangel27

I finally figured it out. It turns out that the system decided it wanted it in scientific notation. Thanks for your help!