Edward C. Jordan Memorial Offering of the First Course under the Indo-US Inter-University Collaborative Initiative in Higher Education and Research: Electromagnetics for Electrical and Computer Engineering

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Edward C. Jordan Memorial Offering of the First
Course under the Indo-US Inter-University
Collaborative Initiative in Higher Education and
Research Electromagnetics for Electrical and
Computer Engineering

• by
• Nannapaneni Narayana Rao
• Edward C. Jordan Professor of Electrical and
  Computer Engineering
• University of Illinois at Urbana-Champaign
• Urbana, Illinois, USA
• Amrita Viswa Vidya Peetham, Coimbatore
• July 10 August 11, 2006

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4.3Magnetic Materials

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Magnetic Materials
are based upon the property of magnetization,
which is the phenomenon of creation of magnetic
dipoles within the material.
Diamagnetism
A net dipole moment is induced by changing the
angular velocities of the electronic orbits.
Dipole moment m IA an
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Paramagnetism
Already existing dipoles are acted upon by a
torque.
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The phenomenon of magnetization results in a
magnetization current in the material which
produces a secondary B.
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Magnetization Current
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To take into account the effect of magnetization,
we define the magnetic field intensity vector, H,
as
mr and m vary with the material, implicitly
taking into account the effect of magnetization.
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As an example, consider
Then inside the material,
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D4.6
For 0 lt z lt d,
(a)
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(b)
(c)