Two electrically charged bodies or simply two electrical charges either attract or repulse each other. Whether they will attract or repulse depends on the nature of charges they hold. If the charges are opposite, they will repulse. On the other hand, if the charges are similar, they will attract each other. More clearly to say, two positive or two negative charges repulse each other. At the same time, one positive charge attracts a negative charge. The repulsion force or the attraction force, whatever may be will have some value. This value depends on some factors. The **Coulomb’s law** gives the exact value of the force acting between two charged bodies.

## Statements of Coulomb’s Law

This law states that the force acting between two electrically charged bodies is directly proportional to the charge of the individual body. inversely proportional to the square of the distance of those two bodies and the permittivity of the medium.

### Expression of Coulomb’s Law

We can write the expression of Coulomb’s law as

Where ‘Q_{1}’ and ‘Q_{2}’ are the charges, respectively. Whereas d is the distance between the charges. The term ε_{0}ε_{r} is the permittivity of the medium.

### Explanation of Coulomb’s Law

Whenever two charged bodies come closer to each other a force acting on them. This force is an electrostatic force. We also call the force as coulombic force. This is because Charles-Augustin de Coulomb had established the expression of this force.

Since this is a force, it has a definite direction. The direction is along the straight line connecting the centers of the charged bodies. This force is outward-directed if both of the charges are similar. Such as these are both positive or both negative. But the same force is inward if the charges are dissimilar. Such as one is positive and other is negative.

- Permittivity (Absolute Permittivity and Relative Permittivity)
- Electric Field Intensity or Electric Field Strength
- Gauss’s Theorem or Gauss’s Law
- Electrical Potential and Potential Difference or Voltage
- Breakdown Voltage and Dielectric Strength
- Electric Flux and Faraday’s Tubes
- Equations of Poisson and Laplace
- Coulomb’s Law Statement and Explanation