Electric Flux Density :

  Def.  The no. Of electric lines of force passing through unit Area constitute of concept of electric flux density. 

                                                                    OR

The ratio of electric flux per unit vector areabis known as electric flux density. 

. It is formula is 

. By nature it is vector quantity and it's direction is same as that of electric lines of force.

Electric Flux Passing through spherical. 

. Consider the given figure in which a sphere is shown the positive point charge is placed at it's center we distribute the given sphere into the "n" no.  of smaller patehes in order to calculate electric flux easily. 

. The electric flux passing through the first patehes is given by 


. The electric flux passing through the Seconf patehes is given by 


. The electric flux passing through the remaining patches is given by 

Now the total electric flux is given by photo. 

. At the magnitude of electric field intensity across different patehes is same so we here