Electrostatics

For a large (ideally infinite) charged plane sheet, the electric field intensity (E) at a point near it is uniform and given by Gauss's law. Assuming it's a non-conducting sheet: where is the surface charge density and is the permittivity of free space ( ).
Given: . The electric field intensity is . The distance from the mid-point does not affect the result for a large plane sheet.

The electric potential (V) created by a point charge (q) at a distance (r) from the charge is given by the formula: where k is Coulomb's constant. From this formula, it is clear that the electric potential V is inversely proportional to the distance r, or directly proportional to .