# Electric Dipole Field

1. Nov 11, 2012

### Septim

Greetings,

I wonder with respect to what coordinates the formulas given for the electric dipole is valid. Also I want to comprehend the difference between pure and physical dipoles and why many books put the origin of the cartesian system they define on the middle point of the electric dipole moment vector( I think they should put the origin at the tail of the vector). Any insight is welcome.

Last edited: Nov 11, 2012
2. Nov 11, 2012

### Simon Bridge

Whatever coordinate system the formulas are given in of course. You need to be specific.
The books are putting the origin half-way between the charges not the dipole vector - which can be drawn anywhere. They put the origin there to make the math/derivations simpler. You can put the origin anyplace you like.

The difference between real and "pure" or ideal dipoles is the same as real vs ideal anything.
Also see: