DIELECTRIC MATERIALS

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LECTURE 16

• DIELECTRIC MATERIALS

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OBJECTIVES

• To explain in your own words what is meant by
  polarization.
• To distinguish between relative permittivity and
  the permittivity of free space.
• To solve electrostatic problems involving
  dielectric materials.

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DIELECTRIC MATERIAL UNDER STATIC CONDITIONS

• APPROACH
• Microscopic point of view
• Macroscopic point of view

E applied
Dielectric material
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MICROSCOPIC POINT OF VIEW
Classical model of an atom
Assume E applied 0
ve
nucleus
- ve
Orbit
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AN ATOM UNDER STATIC CONDITION
Total charge q
Total charge -q
E applied
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MICROSCOPIC DIPOLE MOMENT
q
-q
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MACROSCOPIC POINT OF VIEW
Assume dielectric material is polar material
H20 molecule

- ve

E applied 0
E applied ? 0
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GROUP OF ATOMS
Assume number of atoms is 10
Electric polarization vector
0
of atoms
Electric dipole moment
E applied 0
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E applied ? 0
? 0
Polarized dielectric material.
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REVIEW
Polarization vector
E applied ? 0
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THANK YOU

• QUESTIONS AND ANSWERS