Difference between revisions of "Dipole moment"

From SklogWiki
Jump to: navigation, search
(New page: The '''electric dipole moment''' is a measure of polarity. It is the second term in a multipole expansion of a field (the first one being the monopole, or Coulombic, term.) Its definition,...)
 
m (Some trash was left)
Line 1: Line 1:
 
The '''electric dipole moment''' is a measure of polarity. It is the second term in a multipole expansion of a field (the first one being the monopole, or Coulombic, term.) Its definition, for a system of point charges, is
 
The '''electric dipole moment''' is a measure of polarity. It is the second term in a multipole expansion of a field (the first one being the monopole, or Coulombic, term.) Its definition, for a system of point charges, is
 
<math>\mathbf{p} = \sum_{i=1}^N \, q_i \, \mathbf{r}_i.</math>
 
<math>\mathbf{p} = \sum_{i=1}^N \, q_i \, \mathbf{r}_i.</math>
 
<math>3.33564\times 10^{-33}</math>
 
  
 
For molecular systems, it is customarily given in units of Debyes, after the physicist [[Peter J. W. Debye]].
 
For molecular systems, it is customarily given in units of Debyes, after the physicist [[Peter J. W. Debye]].
 
In SI units, <math>1</math>D equals approximately <math>3.33564\times 10^{-30}</math> Coulomb-meter (exactly <math>10^{-21}</math>C m<math>^2</math>/s divided by <math>c</math>, the speed of light in vacuum). Conversely, 1 C m = <math>2.9979 10^{29}</math>D.
 
In SI units, <math>1</math>D equals approximately <math>3.33564\times 10^{-30}</math> Coulomb-meter (exactly <math>10^{-21}</math>C m<math>^2</math>/s divided by <math>c</math>, the speed of light in vacuum). Conversely, 1 C m = <math>2.9979 10^{29}</math>D.

Revision as of 14:24, 23 May 2008

The electric dipole moment is a measure of polarity. It is the second term in a multipole expansion of a field (the first one being the monopole, or Coulombic, term.) Its definition, for a system of point charges, is \mathbf{p} = \sum_{i=1}^N \, q_i \, \mathbf{r}_i.

For molecular systems, it is customarily given in units of Debyes, after the physicist Peter J. W. Debye. In SI units, 1D equals approximately 3.33564\times 10^{-30} Coulomb-meter (exactly 10^{-21}C m^2/s divided by c, the speed of light in vacuum). Conversely, 1 C m = 2.9979 10^{29}D.