Obviously, we can’t get started with touching upon the ultimate fundamentals of Electronics or Electricity in the first place. One major reason is that, this deals with something not physical, in the sense that, you can’t see, touch, feel and can only visualize mentally about it.

It is imperative to have some knowledge of Fundamental forces of nature in mind while we go ahead.

In Nature, everything happens because of interactions and it is indeed interaction which leads to these forces.

The Four Fundamental Forces of Nature are

1. Gravitational force
2. Weak Nuclear force
3. Electromagnetic force and
4. Strong Nuclear force

Each of the known fundamental interactions can be described mathematically as a field. The gravitational force is attributed to the curvature of spacetime, described by Einstein’s general theory of relativity. The other three are discrete quantum fields, and their interactions are mediated by elementary particles described by the Standard Model of particle physics.

Electromagnetic force

Needless to say we will be digging deeper and deeper into Electromagnetism given the context.

Electromagnetism is a branch of physics involving the study of the electromagnetic force, a type of physical interaction that occurs between electrically charged particles. The electromagnetic force usually exhibits electromagnetic fields such as electric fields, magnetic fields and light.

The electromagnetic force plays a major role in determining the internal properties of most objects encountered in daily life. Ordinary matter takes its form as a result of intermolecular forces between individual atoms and molecules in matter, and is a manifestation of the electromagnetic force. Electrons are bound by the electromagnetic force to atomic nuclei, and their orbital shapes and their influence on nearby atoms with their electrons is described by quantum mechanics. The electromagnetic force governs all chemical processes, which arise from interactions between the electrons of neighboring atoms.

There are numerous mathematical descriptions of the electromagnetic field. In classical electrodynamics, electric fields are described as electric potential and electric current. In Faraday’s law, magnetic fields are associated with electromagnetic induction and magnetism, and Maxwell’s equations describe how electric and magnetic fields are generated and altered by each other and by charges and currents.

How does electricity flow?

To answer this question we need to look at matter itself at a most basic level. Matter is made up of small units called atoms. At this atomic level matter possesses two basic characteristics. Matter has mass and it may have an electrical charge, either positive, negative, or it could be neutral with no charge. Each atom contains three types of particles with different characteristics; positive protons, neutral neutrons, and negative electrons.

Electric current (electricity) is a flow or movement of electrical charge. The electricity that is conducted through copper wires in your home consists of moving electrons. The protons and neutrons of the copper atoms do not move. The actual progression of the individual electrons in a given direction through the wire is quite slow. The electrons have to work their way through the billions of atoms in the wire and this takes considerable time.

How does a flick of the switch cause instantaneous effect?

Atoms are very tiny, less than a billionth of a meter in diameter. The wire is “full” of atoms and free electrons and the electrons move among the atoms. In a typical copper wire there would be trillions of electrons flowing past any given point in the wire every second, but they would be passing that point very slowly. Think of the wire in comparison to a pipe full of marbles. If we push another marble into a filled pipe, then one marble would have to exit the other end. Electrons are like that in a wire. If one moves they all have to move. Thus when you turn on a switch an electrical potential difference (created by a generator) immediately causes a force that tries to move the electrons. If you make one electron move when you turn on a switch, the electrons throughout the wire move, even if the wire is miles long. Therefore when you turn on a switch, the electrons in the light start moving “instantly” as far as we are concerned, i.e. something starts to happen throughout the electrical system. Although the electrons are actually moving through the wire slowly, we say that the speed of electricity is near the speed of light (extremely fast). What we really mean is that the effects from the electricity occur “instantly.” The light comes on the instant you flip a switch. You do not have to wait for electrons to flow from the switch to the light.

Courtesy: https://www.uu.edu

The strength of an electric current is measured with a unit called the ampere, sometimes used in the short form amp or abbreviated A. The ampere is nothing more than a measurement of how many charge carriers (in most cases, electrons) flow past a certain point in one second. One ampere is equal to 6,240,000,000,000,000,000 electrons per second. That’s 6,240 quadrillion electrons per second.