# Electric Field At An Axial Point Of A Dipole | cbse24.com

### The electric field at an axial point of an electric dipole:

As shown in figure an electric dipole consisting of charge +q and -q , separated by distance 2a and placed in a vacuum . Let P be a point on the axial line at distance r from the center O of the dipole on the side of the charge +q. The electric field at an axial point of a dipole

By this picture, you can see the resultant electric field at an axial point of a dipole this value is 3.51 V/m but if you start increasing distance mean point p on the axial point of dipole than field start decreasing. The electric field at an axial point of a dipole at a distance

so here you can see that if I increase the distance P on the axial point of a dipole than the electric field start decreasing and its value will be  1.72 V/m. so what I found? , with increasing the distance the electric field will start decreasing. The electric field at an axial point of a dipole at a far distance

### Calculation of the net electric field at an axial point of a dipole:

1. Electric field due to charge  -q at point P is

..................(towards left)

2. Electric field due to charge  +q at point P is

.........................(towards the right)

Note- Where    is the unit vector along the dipole axis from -q to +q

Hence the resultant electric field at point P is

or

Here   P= q x 2a = dip[ole moment .
for  r>>a  , a2  can be neglected compared to r2

.......................(towards right according to vector addition)

Note- The electric field at any point of the dipole acts along the dipole axis from negative to the positive charge i.e in the direction of dipole moment .

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