Electric field of an electric dipole
o
o
o
o
Total charge of an electric dipole is zero but since the charges are separated by some distance the electric field do not cancel out .
Dipole moment is the mathematical product of the separation of the ends of a dipole and the magnitude of the charges ( 2a x q ).
Some molecules like H 2 O , have permanent dipole moment as their charges do not coincide . These molecules are called polar molecules .
Permanent dipoles have a dipole moment irrespective of any external Electric field .
Electric field of an electric dipole
Electric field of an electric dipole at a point in space depends upon the position of the point .
o
o
The dipole field at a point is inversely proportional to the cube of distance from the center to the point .
For a very small dipole , the 2a approaches zero . This is called point dipole .