CXosnider a rectangular loop carrying a curent i as shown in teh figure. Point P is located a distance x from the cneter of the loop. Find an epxression for tha mgnetic field at P due to the current loop assuming that P is(adsbygoogle = window.adsbygoogle || []).push({}); very far away.

WIth [itex] \mu = iA = iab [/itex] obtain an expressionsimilarto that of a circular looop which is [tex] B = \frac{\mu_{0} \mu}{2 \pi x^3} [/tex]

for the field due to a distant dipole at points in the plane of the loop (perpendicular to the axis.)

Hint: Opposite sides can we treated together but consider carefully the direction of B due to each side

Well

for vertical sides (sides of length b) the magnetic field due to them both is zero because of the right rule, their magnetic field are in opposite directions and equal (equal becuase x >> a/2)

for the hirzontal sides however, the same doesnt not apply, the magnetic field is not zero since due to them both th magnetic field points out of the page.

not since x is big am i right in assuming taht [itex] \sqrt{x^2 + \frac{b^2}{4}} \approx x [/itex] ??

in that case

[tex] B = \frac{2 \mu_{0} i}{2 \pi x} = \frac{\mu_{0} i}{\pi x} [/tex]

is this right?

im not sure ho to proced with teh second part of the quesiton..

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# Homework Help: Current loop

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