This one is again from Griffiths.(adsbygoogle = window.adsbygoogle || []).push({});

a) Find the force on a square loop of side 'a' placed at a distance 's' from an infinite wire. Both the loop and the wire carry a current 'I'.

I found the magnitude of the magentic field using Biot-Savart's law:

[tex]B = \frac{\mu_0 I}{2\pi s}[/tex]

The force is given by:

[tex]\vec F_{mag} = I\int\left(d\vec l \times \vec B\right)[/tex]

"dl" is a wire element.

So, when I consider only the magnitude:

[tex]F = \frac{\mu_0 I^2}{2\pi s}\int dl[/tex]

Here the wire is infinite, so how is it possible to integrate over the length of the wire?

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# Homework Help: Square loop carrying current near a wire

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