I'm unsure what I'm doing wrong here... it has to be something. So let me explain the problem:(adsbygoogle = window.adsbygoogle || []).push({});

I'm supposed to rank the net magnetfic field strength for various arrangements. In all of the arrangements the magnitude of the current is the same. The distance between each of the charges is the same. We are supposed to find the magnetic field in the center of each arrangement. (The center of the square)

The first arrangement looks like this (please excuse the ascii art)

(EDIT: I've been trying to make this thing look pretty. I give up on it. It is just supposed to be a square)Code (Text):

[*]------[*]

| |

| |

| |

[*]------[*]

This is supposed to be a cross sectional area of four wires that are run in parallel. The distance between each wire is the same. [*] means the direction of the current is running into the page.

Ok, so this is how I "thought" I should solve this problem.

We can use [tex] B = \frac{\mu_0 I}{2 \pi r} [/tex] to model the field strength at a distance [itex] r [/itex] from each wire. If we let [*] be a positive direction. Next, we use vector superposition to get the net magnetic field.

Thus:

[tex] B_{net}=B_1+B_2+B_3+B_4 = \frac{\mu_0}{2 \pi r} \sum_{n=1}^{4} I_n [/tex]

We can drop the terms that are not changing because it's not relevent for the ranking. Thus:

[tex] B_{net} = I_1+I_2+I_3+I_4 [/tex]

So for the ASCII diagram I have, then:

[tex] B_{net} = 4I [/tex]

However, the example we were given states that [itex] B_{net} = 0 [/itex].

How am I not modeling this correctly. I guess I'm having a hard time visualizing how the circular magnetic fields are interacting with each other.

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# Homework Help: Simple EM Problem (not to me for some reason)

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