What is meant by the term dipole?

[Xian]

There is magnetic and electric dipole. The word itself "dipole" is very ambiguous to me. Also "dipole moment" (my guess it it is just a pause in a frame of time depicting the fields or just capturing that moment, something like that)?

[Ophiolite]

Dipole: the observation that magnetic and electric charges tend to exist as opposites. Negative, or positive electric charges; north, or south seeking magnetic poles. Two poles, hence dipole.

 

A moment is a combination of some force, or property of a body and distance. So the electric dipole moment relates to the magnitude of the charges on two particles and the distance between them.

 

Disclaimer: This is an 8th grade understanding of the terms, but may meet your needs.

[swansont]

The moment is defined such that when you take the cross product with the appropriate field, you get the torque on the object. Thus p X E gives the torque on an electric dipole, where p is the electric dipole moment, and similarly for u X B, where u is the magnetic dipole moment.

[Mike Smith Cosmos]

This may, or may not, help in understanding electrical and magnetic dipoles.

I come from an Electronic/Radio background . Dipoles and electromagnetism are at the core of operations in this field .
See following drawing .



Explanation which could possibly help :-

The green pole split in the middle is called a DIPOLE . You may have seen them sticking up on top of people's houses , being the old way of receiving TV programmes. It is still used to transmit some signals from tall masts you may see dotted around towns and on top oh hills. Like a violin string , it is a very useful way of transmitting and receiving electro - magnetic waves or signals ( via these DIPOLES ) .

Basically because one sets up a standing wave ( like shaking a skipping rope or plucking a guitar/ violin string )
Why it works so well.
Is the far ends (moment ) are electrically zero and magnetically a maximum.
The centre is electrically maximum and magnetically zero ( again a moment )

Strings and electro magnetism ' loves'. To exist in this configuration . OSCILLATING . Setting up this stable , efficient, configuration or moment.

Perhaps in biology this happens also ( not my field )

Mike

Ps the electrical and magnetic fields are polarised at 90 degree in space to each other . Shown by pink and blue signals illustrated diagrammatically at 90 degrees to each other .

Edited November 23, 2014 by Mike Smith Cosmos