Question

what is coulomb law in electrostatic define complete please frnds

Answer 1

The coulomb's law states that : the magnitude of the electrostatic force of attraction or repulsion between two point charges is directly proportional to the product of the magnitudes of charges and inversly proportional to the square of the distance between them. The force is along the straight line joining them

Answer 2

Coulomb law is defined as when an an attractive or repulsive force act on a point charge by the another point charge then this force is directly proportional to the product of the their charge and is inversly propotional to the square of distance between them.

that is
f proportional to q1*q2
f proportional to 1/r^2

so combining these two

f proportional to q1q2/r^2
f = k q1q2/r^2

where k is proportionality constant and its value is
$\frac{1}{4\pi \:abslum \: knot } \: \: \frac{q1 \times q2}{r^{2} }$
also k = 9 * 10^9