A point charge is a hypothetical charge located at a single point in space. The electric field due the point charge (Q) is radial and it decreases with increasing distance from the charge.

Electric field strength of a point charge:

E = k Q/d² . .............................................. (2-3)

Where E = electric field

k = Coulomb's constant

Q = electric point charge

d = distance between the charge and the test charge

Note: Force depends only upon the magnitude of the point charge producing the field, and not on the value of the test charge. The resultant electric field due to many- point- charge is a vector quantity, determined by using vector rules to determine the magnitude and direction of the resultant electric field at a particular point (adding the individual fields due to each charge at that point according to vector rules).