Download presentation

Presentation is loading. Please wait.

1
**Electric field of a Polarized Object**

© Frits F.M. de Mul E-field of a polarized object

2
**Electric field of a Polarized Object**

Available: An external E-field: Eex. Eex A dielectric object will become polarized. Question: Calculate E-field produced BY (not: IN) the polarized object. E-field of a polarized object

3
**Electric field of a Polarized Object**

Analysis and symmetry Approach to solution Calculations Conclusions E-field of a polarized object

4
**E-field of a polarized object**

Analysis and Symmetry Z Y X Coordinate axes: assume Z-axis // Eex Eex Result of polarization: Dipole distribution: n dipoles/m3 ; each dipole moment p [Cm] Assume: p // Eex ; n and p homogeneous E-field of a polarized object

5
**E-field of a polarized object**

Approach to solution Eex Z Y X v Question: calculate E-field in arbitrary point P outside v P Approach: = calculate potential V ; = E from V by differentiation Distributed dipoles: dV- integration over volume elements dv filled with dp. E-field of a polarized object

6
**E-field of a polarized object**

Calculations (1) Dipole: Eex Z Y X P Z' r er dp dz volume element dv with dp = np.dv = np.dS..dz ; with dS Z-axis E-field of a polarized object

7
**E-field of a polarized object**

Calculations (2) Z Z' dp Eex cross section through P and Z’-axis : P r dS rb rt zt : top zb : bottom dz er r P Y X E-field of a polarized object

8
**E-field of a polarized object**

Calculations (3) P rb rt r zt zb dS dz-integration dr-integration : dr = -dz.cos dz = -dr / cos r dz dr P E-field of a polarized object

9
**E-field of a polarized object**

Calculations (4) dS zt rt r P rb zb “Polarization” P = np dz r P dr E-field of a polarized object

10
**E-field of a polarized object**

Calculations (5) Eex Z Y P Z' X r er dp dz P dS P.dS = P.dS bound charges: db = P.dS E-field of a polarized object

11
**E-field of a polarized object**

Conclusions P Eex Z Y X rbottom rtop + - bound charges: db = P.dS Conclusion: the field of a polarized volume is equivalent to that of bound surface charges (provided homogeneous polarization) + - the end E-field of a polarized object

Similar presentations

OK

1 ENE 325 Electromagnetic Fields and Waves Lecture 1 Electrostatics.

1 ENE 325 Electromagnetic Fields and Waves Lecture 1 Electrostatics.

© 2017 SlidePlayer.com Inc.

All rights reserved.

Ads by Google

Ppt on phonetic transcription online Ppt on recycling of waste fabric Ppt on social contract theory summary Ppt on earth day 2014 Ppt on layer 3 switching Ppt on aircraft emergencies youtube Ppt on workplace etiquette powerpoint presentation Ppt on responsive web design Ppt on political parties and electoral process united Marketing mix ppt on sony entertainment