# Homework Help: Ampere's law problem

1. Apr 5, 2009

### Crazy Gnome

1. The problem statement, all variables and given/known data
A conducting slab of thickness a is bounded by the planes z= $$\pm$$a/2 and carries a uniform current density J=J (y hat)

Use the integral form of Ampere's law to to find magnetic field everywhere
2. Relevant equations

Integral for of Amperes law: Integral (B \bullet ds) = \mu 0 Jenclosed

3. The attempt at a solution

All of the examples in class and in the book use cylindrical symmetry so I was a bit perplexed as how to approach taking an integral over a closed path dotted into a B in cylindrical coordinates.

Last edited: Apr 5, 2009
2. Apr 5, 2009

### Redbelly98

Staff Emeritus
Try using a rectangular loop for the integration. Each leg of the loop is either perpendicular or parallel to B.