# Coulomb's Law

Written by Jerry Ratzlaff on . Posted in Electrical Engineering Coulomb's law is the magnitude of the electrostatic force between two electric charges.  In case of more than two electric charges, the superposition principle in addition to coulomb’s law is applied to calculate the net electronic force acting on any one charge.  According to this superposition principle, the total force acting on a given charge is equal to the vector sum of forces exerted on it by all the other charges.

## Coulomb's Law formula

$$\large{ F_e = k_e \; \frac{q_1 \; q_2} {l^2} }$$
Symbol English Metric
$$\large{ F_e }$$ = electrostatic force $$\large{lbf}$$ $$\large{N}$$
$$\large{ k_e }$$ = Coulmbo's constant $$\large{\frac{lbf-ft^2}{F^2}}$$ $$\large{\frac{N-m^2}{C^2}}$$
$$\large{ q_1 }$$ = electric charge $$\large{C}$$ $$\large{C}$$
$$\large{ q_2 }$$ = electric charge $$\large{C}$$ $$\large{C}$$
$$\large{ l }$$ = distance between the two charges $$\large{ft}$$ $$\large{m}$$

## Coulomb's First Law

Two charged particles of same charge (positive or negative) will repel each other and two charged particles of opposite charges (one positive and one negative) will attract each other.

## Coulomb's Second Law

The force of attraction or repulsion between the two electrically charged particles is directly proportional to the product of magnitudes of two charges and inversely proportional to the square of the distance between two charges. 