# Homework Help: Find magnetic field of infinitely closely spaced loop

1. Mar 25, 2010

### cloudy14

Those loop are very closely spaced, with current I going in anticlockwise direction. The stack of loop have a total length of d. What is the magnetic field, B at the point X?

(I assume the X to be directly on top of the center of the loops.)

The attempt at a solution:

Help!! I don't even know where to start. I tried to used the Ampere's Law
$$\oint{B \cdot dl}=\mu_0I_{enc}$$
But realised I ended up getting the results for a cylinder.