“What is the distance between two lines of force produced by a charge or the distance is zero between them and what is the diameter of electron?” – Ela posted.
The electric field lines are imaginary lines used to represent the electric field visually. The electric field lines are imagined or drawn relatively closer where there is greater electric field. (Though electric flux is often defined as the number of field lines per unit area, it is not so. Electric flux cannot be talked in terms of just numbers. That definition is just to make a quick idea related to the lines in a given situation. To cross check, just calculate the electric flux from a proton and try to draw that much number of lines around a point)
The radius of electron has been calculated from Mass Energy relation as 2.817 940 3267 x 10-15m
Therefore, Diameter of an electron = 5.635880578916 x 10-15m
Please note that the above value is just a theoretical estimation. The actual size of electron is not experimentally determined.
Refer to http://en.wikipedia.org/wiki/Classical_electron_radius for more