Introduction To Electrostatics. Electrostatics is the study of charges at rest under the action of electric force.
An electric force is a force that holds positive and negative charges that make up atoms and molecules.
Meaning everything is made up of an electric force.
Thus, we owe our existence to this electric force.
We know that there are two types of charges, positive and negative.
And these two charges attract each other while like charges, i.e. positive and positive or negative and negative charges repel each other.
Now we investigate the quantitative nature of these forces.
The first measurement of the force between electric charges was made in 1784 AD by Charles Coulomb.
He deduced a law, known as Coulob’s law, which states:
“The force between two point charges is directly proportional to the product of the magnitudes of charges and inversely proportional to the square of the distance between them.”
Which can be mathematically expressed as
Where F is the magnitude of the mutual force that acts upon the two charges q1, q2.
r2 is the square of the distance between these two charges.
And K is the constant of proportionality and its value depends on the medium in which F, q, and r2are being measured.
If the medium between two charges is free space, then the K is represented as
Where is an electrical constant, known as permittivity of free space.
In SI units, its value is 8.85 1012 C2 N1m2.
The K in free space is considered to be 9109 Nm2C-2.