Chapter 1

Overview of Atoms and Charged Particles

Everything is composed of atoms at the tiniest level.
Protons, electrons, and neutrons are the three primary constituents of an atom.
Electrons are negatively charged, protons are positively charged, and neutrons are neutral.
Understanding electricity depends critically on how these charged particles behave.

Charge Interaction:- Electric Charge

Electric charges interact with one another, which is their basic characteristic.
When two positive or negative charges are in opposition to one another, they repel one another.
The attraction between positive and negative charges results from the attraction of opposite charges.

Insulators and conductors: -

Materials that permit the unrestricted flow of electric charges are called conductors.
Electric current flows through metals because electrons are free to roam about and are not tightly bonded to atoms.
Examples are:-

 1. aluminium and copper.
2. Warm-weather components

Materials that act as insulators prevent electric charges from moving freely.
In insulators, electrons are firmly bonded to atoms, limiting their mobility.
Glass, rubber, and wood are among examples.

Coulomb's Law:-

Coulomb’s Law mathematically describes the force between two point charges.
The force (F) is directly proportional to the product of the charges (q1 and q2) and inversely proportional to the square of the distance (r) between them.
It is expressed as F=r2kq1q2
where k is Coulomb’s constant.

Electric Field:-

An electric field is a region in space around a charged object where another charged object experiences a force.
It is a vector field, meaning it has both magnitude and direction.
The electric field at a point is the force experienced by a positive test charge placed at that point.

Electric Field Lines:-

Electric field lines are imaginary lines used to represent the direction and strength of the electric field.
Arrows on the lines indicate the direction of the force that a positive test charge would experience.
The density of field lines is higher where the field is stronger.

Electric Flux:-

Electric flux measures the flow of an electric field through a given area.
It is the product of the electric field strength, the area, and the cosine of the angle between the field and the normal to the area.


Gauss’s Law:-

Gauss’s Law relates the total electric flux through a closed surface to the total charge enclosed by the surface.

It provides a powerful method for calculating electric fields in situations with high symmetry, simplifying complex problems.

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