dorsal/arxiv
View SchemaA dipole in a dielectric: Intriguing results and shape dependence of the distant electric field
| Authors | R. L. P. G. Amaral, N. A. Lemos |
|---|---|
| Categories | |
| ArXiv ID | physics/0210066 |
| URL | https://arxiv.org/abs/physics/0210066 |
| DOI | 10.1119/1.1522697 |
| Journal | Am.J.Phys. 71 (2003) 392-396 |
Abstract
The field of a point electric dipole in an infinite dielectric is obtained by placing the dipole at the center of a spherical cavity of radius $R$ inside the dielectric and then letting $R\to 0$. The result disagrees with the elementary answer found in textbooks. The mathematical and physical reasons for the disagreement are discussed. The discrepancy is confirmed by the same limiting procedure applied to a uniformly polarized sphere embedded in the dielectric. We next solve the same problem for a polarized spheroid immersed in an infinite dielectric and find that the asymptotic potential shows an unexpected shape dependence, even after taking the limit of an arbitrarily small spheroid. By considering both oblate and prolate spheroids and taking appropriate limits, we recover either the elementary textbook answer or the previous result found for the polarized sphere.
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"abstract": "The field of a point electric dipole in an infinite dielectric is obtained by\nplacing the dipole at the center of a spherical cavity of radius $R$ inside the\ndielectric and then letting $R\\to 0$. The result disagrees with the elementary\nanswer found in textbooks. The mathematical and physical reasons for the\ndisagreement are discussed. The discrepancy is confirmed by the same limiting\nprocedure applied to a uniformly polarized sphere embedded in the dielectric.\nWe next solve the same problem for a polarized spheroid immersed in an infinite\ndielectric and find that the asymptotic potential shows an unexpected shape\ndependence, even after taking the limit of an arbitrarily small spheroid. By\nconsidering both oblate and prolate spheroids and taking appropriate limits, we\nrecover either the elementary textbook answer or the previous result found for\nthe polarized sphere.",
"arxiv_id": "physics/0210066",
"authors": [
"R. L. P. G. Amaral",
"N. A. Lemos"
],
"categories": [
"physics.class-ph",
"cond-mat",
"gr-qc",
"hep-th",
"physics.ed-ph"
],
"doi": "10.1119/1.1522697",
"journal_ref": "Am.J.Phys. 71 (2003) 392-396",
"title": "A dipole in a dielectric: Intriguing results and shape dependence of the distant electric field",
"url": "https://arxiv.org/abs/physics/0210066"
},
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