Question

State and explain Coulomb's law in electrostatics.

Answer 1

Coulomb's law in electrostatic states that a charge at rest $q_1$ applies a force $F$ on the other charge $q_2$, also at rest, which are separated by a distance $r$ such that the force is directly proportional to the product of both charges and inversely proportional to the square of the distance between them.

$\therefore$ $F\propto q_1{q}_2$ and $F\propto \frac{1}{r^2}$

Thus we get $F\propto \frac{q_1{q}_2}{r^2}$

$⟹$ $F=\frac{k{q}_1{q}_2}{r^2}$ where $k=\frac{1}{4\pi {ϵ}_o}$