Columb, through his experiments, found that the force between two magnetic poles placed in a medium is
i. Directly proportional to their pole strengths,
ii. inversely proportional to the square of the distance between them, and
Where F = force between two magnetic poles,
m1, m2 = pole strengths of the two poles respectively,
d = distance between the poles,
µ = absolute permeability, and
k = constant.