Register to reply

Find all the bound currents. What is the net bound current flowing down the wire?

by blueyellow
Tags: bound, current, currents, flowing, wire
Share this thread:
blueyellow
#1
Nov12-11, 07:39 AM
P: 241
1. The problem statement, all variables and given/known data

A current I flows down a long straight wire of radius a. The wire is made of linear material with susceptibility chi(subscript m), and the current is distributed uniformly.

i) what is the magnetic field a distance s from the axis?
ii) Find all the bound currents. What is the net bound current flowing down the wire?

3. The attempt at a solution
i) I found a similar homework question on this website:

http://maxwell.uncc.edu/gjgbur/cours...k11answers.pdf

which says that B=[mu Is/(2pi a^2)]phi-hat
ii) J(subscript M)= curl M
= [(chi(subscript M) I)/(pi a^2)] z-hat

integral of [(chi(subscript M) I)/(pi a^2)] z-hat dS
= loop integral of [(chi(subscript M) I)/(pi a^2)] z-hat. dl
=0

why does J(subscript M) have to be integrated over the surface, though?

j(subscript m)=M cross n-hat
=[- chi(subscript M) Is/(2 pi a^2)]z-hat ?

why does http://maxwell.uncc.edu/gjgbur/cours...k11answers.pdf
say that j(subscripr m) has to be integrated over the perimeter? How do I do this? And why is the result of it supposed to be zero? Please help
Phys.Org News Partner Science news on Phys.org
Fungus deadly to AIDS patients found to grow on trees
Canola genome sequence reveals evolutionary 'love triangle'
Scientists uncover clues to role of magnetism in iron-based superconductors

Register to reply

Related Discussions
Equivalence between bound electric currents & bound magnetic charge in magnetization Classical Physics 6
Quick question regarding bound currents. Classical Physics 2
How do we find the least upper bound and greatest lower bound? Calculus & Beyond Homework 2
Bound currents problem Advanced Physics Homework 2
Bound currents Classical Physics 2