Electrostatics Formula, Definition, Equations, Examples

Electrostatics is one of the branches of physics that helps explain these fantastic wonders. This is important because it helps us to explain natural electrostatic phenomena and how to solve fundamental problems in this field.

Humans observed phenomena related to accumulated commissions on surfaces. If we rub two non-conducting surfaces together, both become charged. We can observe this by bringing a conductive surface close to any object sensitive to electrostatic forces, such as our hair. When we rub a plastic ruler on a woolen rug and then bring it close to our head, the hair on our head will look attractive to the ruler.

Electrostatics

These and many other examples in our daily life indicate the existence of forces exerted by electric charges.

The study of static electric charges is called Electrostatics. Coulomb’s law, discovered by Charles Augustine de Coulomb, was the most important discovery that made all other discoveries possible.

Coulomb’s law

Coulomb’s law provides a direct relationship between the size of two charges, the distance between two charges and their force exert on each other. The law states that F = 14πε0q1q2r2

Here, F is the force between charges q1 and q2 and charges r is the distance between the two charges.

Note: In the above equation, both charges are assumed to be at a static position or rest.

Gauss’s law of Electrostatics:

Electrostatics examines the interaction between static electric charges.

Gauss’s law finds the electric field when the charge is continuously distributed in an object with a symmetrical geometry, such as a sphere, cylinder or plane. Gauss’s law follows Coulomb’s law and the principle of superposition.

Gauss’s law provides the relationship between the electric current through a closed surface and the amount of charge enclosed. Use Gauss’s law around a cylindrical surface to express the electric field due to an infinite plane sheet uniformly charged.

Gauss’s law for Electrostatics states that the total electric current through a closed surface is divided by the permittivity of the medium into the charge covered by the surface.

Where,

• ΦE is the amount of electric flux,
• E⃗  is the electric field,
• dS⃗  is a very tiny surface element,
• Q_enc is the total charge,
• ε₀ is the permittivity of the medium.

What is Electrostatic Pressure?

Electrostatic pressure is the tension caused by mutual repulsion between charges of the same sphere on a sphere. As a rubber band is stretched outward from all points, stress is developed in it.

Suppose the conductor is at rest in an electric field. If a conductor has charge distributed over its surface, that surface charge experiences a net surface tension due to the electric field. This pressure is equal to the average of the electric fields at all points of the conductor’s surface. This average becomes: P = 02E2

Here, P is the pressure, ε0 is the absolute permittivity of free space E is the electric field in which the conductor is placed.

Note: This pressure always pushes the conductor into the field regardless of the sign of the surface charge.

What are the applications of Electrostatics?

Electrostatics plays a significant role in everyday life. Various applications of Electrostatics include photocopiers, defibrillators, paint spraying, electrostatic precipitator, etc.

Computer peripherals like liquid crystal displays (LCD), keyboards, and touchpads work on the principle of Electrostatics. Electrostatics are used in agricultural operations, such as spraying plants and sorting seeds. Electronic components like capacitors, resistors etc., work based on Electrostatics.

What is Electrostatic Field?

Once the charge distribution of a particle is known, we can determine the electric field of that particle. We know that matter forms point charges (electrons and protons), and each point charge creates a field.

If a particle carrying unit positive charge is placed at a certain point, it experiences a force called electric force F. The region of this force is called the electric field region.

Conclusion:

Electrostatics is one of the fundamental topics in potential theory, as it is the source of many equations and fundamental concepts used in electromagnetic theory.

The underlying theory of Electrostatics is that if the surface of an object comes into contact with other surfaces, a charge is created on its surface. This charge can be positive or negative, and charges attract each other while charges repel each other.