(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

A square of edge a lies in the xy plane with the origin at its center. Find the value of the magnetic induction at any point on the z axis when a current I' circulates around the square.

2. Relevant equations

B=u/4pi * lineint[(I'*ds' x R)/R^3)]

3. The attempt at a solution

I guess you've got the 4 different sides of the square, I assumed by "circulating" it meant it goes around, so opposite sides the current is going opposite directions. The way I did this, let's say it's going around counter-clockwise, for the side on the right running parallel to the x axis with the current travelling in the positive x direction...

(capital letters = unit vectors)

ds'=dx'X

R=-x'X-a/2Y+zZ

ds' X R = -(zY+a/2*Z)dx'

R^3 = (x'^2+a^2/4+z^2)^(3/2)

so when I integrate that, I'm just gonna say k=uI'/4pi and...

-k{4a(zY+a/2Z)sqrt(2)/[sqrt(a^2+2z^2)*(a^2+4z^2)]}

is my approach even right? I carefully repeated that for all 4 sides and added them, but didn't get the right answer(I don't have the "answer" per se, rather just the value in the middle of the square, which I didn't get right)

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: A magnetic induction question

**Physics Forums | Science Articles, Homework Help, Discussion**