Electrical Engineering Material

1. ELECTRICAL ENGINEERING
MATERIALS: MAGNETIC MATERIALS
MR. ASIF L. JAMADAR

2. INTRODUCTION
 Magnetic materials & non-magnetic materials
 Magnetic field produced by a current in a coil of wire
 An atom should act like a magnet (with each electron charge of 1.6 X 10-19 C)
 Circles the atom once in about 10-16 s……
Current (A) = Charge (C) / Time (s)
Current = (1.6 X 10-19 ) / (10-16 ) = 1.6 X 10-3 A
 Magnetic field produced by an electron in an atom is often cancelled by an
oppositely revolving in the atom
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3. 3
 The field due to spinning motion is generally stronger than the field due to
orbital motion
 Magnetic / non-magnetic material & spinning of electrons
 Classification of magnetic materials is done on the basis of orientation of
electron spin
 The behavior of magnetic materials can be understood

4. BIOT-SAVART’S LAW
 Biot-Savart’s law states that the magnetic flux density dB or magnetic field
strength dH at a point due to a current element I dL is given by,
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5. AMPERE’S CIRCUITAL LAW
 Ampere’s circuital law states that the line
integral of magnetic strength H along any
closed path is exactly equal to direct
current enclosed by the path
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6. MAGNETIC FLUX DENSITY & MAGNETIC FLUX
 In magnetic field, the principle quantities are magnetic field intensity H &
magnetic flux density
B = μ H
μ = μ0 μr
 Magnetic flux density can be defined as flux passing through the per unit area
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7. MAGNETIC DIPOLE
 Dipole moment
 The vector direction of dipole moment
Dipole moment pm = current in the loop X area of loop
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8. THANK
YOU
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