Electric Field at any point due to an Electric Dipole
The dipole moment p of the dipole can be re-solved into two components:
(i) The component p cosθ along OP and
(ii) The component p sinθ along a direction perpendicular to OP.
The point P lies on the axial line of dipole A1B1. Therefore, electric
field intensity at point P due to dipole A1B1.
Further, point p lies on the equatorial line of dipole A2B2.
Therefore, electric field intensity at point P due to dipole A2B2,
(along PL, perpendicular to PK)
The resultant electric field intensity point P,
Force between Two short Dipoles
Consider two short dipoles separated by a distance r. There are two possibilities. If the dipoles are parallel to each other.
As the force is positive, it is repulsive. if 
the
force is attractive.
If the dipoles are on the same axis.
As the force is negative, it is attractive.