Finding B, M, and H for an infinite conducting slab

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SUMMARY

The discussion focuses on calculating the magnetic field (B), auxiliary field (H), and magnetization (M) for an infinite conducting slab with magnetic susceptibility χm and a volume current density J = J0z/a. The key equations referenced include Ampere's law and the definitions of H and bound currents. The user expresses confusion about defining an Amperian loop and determining the magnetization, ultimately concluding that finding H using Ampere's law is the necessary first step.

PREREQUISITES
  • Understanding of Ampere's law and its application in magnetostatics
  • Familiarity with magnetic susceptibility and its role in material properties
  • Knowledge of magnetization (M) and bound currents in electromagnetic theory
  • Ability to define and utilize Amperian loops for magnetic field calculations
NEXT STEPS
  • Study the application of Ampere's law in different geometries, particularly infinite slabs
  • Learn about the relationship between magnetization (M) and bound currents (Jb)
  • Explore the concept of magnetic susceptibility (χm) and its impact on magnetic fields
  • Investigate examples of calculating H, B, and M in various conducting materials
USEFUL FOR

Students and professionals in physics and electrical engineering, particularly those studying electromagnetism and magnetic materials.

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Homework Statement


We have an infinite slab of conducting material, parallel to the xy plane, between z = −a and z = +a, with magnetic susceptibility χm. It carries a free current with volume current density J = J0z/a in the x direction (positive for z > 0, negative for z < 0). The integrated current density across the whole slab is therefore zero. What are H (auxiliary field), B (magnetic field), and M (magnetization) (magnitude and direction)? What is the bound current?

Homework Equations


Ampere's law: ∫B⋅dl=μ0*Ienc
Magnetic dipole moment: m=I*a
Bound currents: Jb=∇×M (volume bound current) and Kb=M×n (surface bound current)
Definition of H: H=(1/μ0)*B-M
Ampere's law in terms of H: ∫H⋅dl=Ifenc

The Attempt at a Solution


I'm not really even sure where to start with this one. I thought finding the magnetization was what I needed to do as a starting point but I'm not entirely sure how to do that. I also was wondering if my starting point should be to find H by defining an Amperian loop inside the slab, but I'm also unsure of how to do that because the current is equal in magnitude and opposite in direction in the top and bottom sections of the slab so won't it just cancel out giving me an result of H = 0? If anyone could point me in the right direction it would be appreciated.
 
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Someone please help me. I have no idea what I'm doing and need to get this assignment done ASAP. I know now that I need to find H first using Ampere's law but am having a hard time understanding how to define my Amperian loop
 

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