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

A packed bundle of 100 long, straight, insulated wires forms a cylinder of radius R = 0.600 cm.

If each wire carries 4.50 A, what are the magnitude and direction of the magnetic force per unit length acting on a wire located 0.200 cm from the center of the bundle?

2. Relevant equations

[tex]F/L = IB [/tex]

[tex]B = (\frac{(\mu)I}{2(\pi)R^{2}})r [/tex]

3. The attempt at a solution

I plugged in the various values getting:

[tex]F/L = (450)((4\pi X 10^{-7}*450)/(2\pi(.006^{2}))(.002)[/tex]

That equals 2.25 N/m which is orders of magnitude off. Can anyone tell me what I am doing wrong here? This problem is in the book with slightly different numbers and the answer is is X.XX mN/m. Thanks for the help.

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# Homework Help: Magnetic Force Per Unit Length

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