Electric dipole

1)Electric dipole is a combinations of two equal and opposite charges +q and -q

2)The distances between the two charges is 2a.

As shown below --->


Electric field due to

dipole on the axis

 



Now X is a position where electric field intensity has to be calculated at a distance r from the origin of the dipole, as shown in the above.

  

Now distance from +q and -q to the X is ---->

 


Therefore electric field at X due to positive +q is ---->



electric field at X due to positive -q is ---->

 

Therefore net electric field intensity at X is ---->

 



 


When  r≫a