Designing a simple magnetic field gen with a straight wire. Need current density

AI Thread Summary
The discussion focuses on designing a magnetic field generator using a solid metal wire with a specified radius of 2mm. The goal is to achieve a magnetic field of 7.5 x 10^-13 Tesla at a distance of 8mm from the wire's axis, utilizing Ampere's Law for derivation. The current density, J, is defined as J = I/(π*r^2), where I is the current flowing through the wire. Participants are attempting to visualize the problem through diagrams, but there are concerns about their accuracy. The conversation emphasizes the need for a clear understanding of the equations involved in calculating current density and magnetic fields.
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Homework Statement


Need to design a simple magnetic field generator of radius a= 2mm. The solid metal wire must carry a current density, jw, uniformly distributed over its cross section. The current density that must be found must have a magnetic field at a radial distance of r= 8mm from the axis of the wire is 7.5 10^-13 Tesla. Ignore end effects. Must develop the equation using Ampere's Law as the beginning derivation.


Homework Equations


I=∫J*da
A=r*r*∏
B∫J*ds

The Attempt at a Solution



I am have been trying to start off this by drawing a diagram but I don't even think it is correct.

http://imageshack.us/photo/my-images/440/finalprep.png/
 
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Also I forgot an equation jw inside is

J=(I)/(∏*r*r)
 

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