Two charges, each of `5 mu C` but opposite in sign, are placed 4 cm apart. Calculate the electric field intensity of a point that is a distance 4 cm from the mid point on the axial line of the dipole.

Explanation

We can not use formula of short dipole here because distance of the point is comparable to the distance between the two point charges.
`q = 5 xx 10^(-6)C, a = 4 xx 10^(-2)m, r = 4 xx 10^(-2)`m

`E_("res") = E_(+) + E_(-) = (K(5mu C))/((2cm)^(2)) - (K(5 mu C))/((6 cm)^(2))`
`= (144)/(144 xx 10^(-8))NC^(-1) = 10^(8)NC^(-1)`