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Basics of Electricity

 Basics of Electronics and electricity

Although we realize the effects of electrical phenomena, many of them cannot be visualized. For example, electric current cannot be seen, yet we can feel its effects, such as electric shock, or see a light bulb light up, a motor running, etc.

Basics of Electronics and electricity

Atomic theory is used to satisfactorily explain the basic principles of electronics. Let's look at some:

Matter: It's everything that occupies a place in space, among the examples are, steel block, piece of wood.

Molecule: It is the smallest portion of matter, which retains its properties, as an example the water molecule (H2O)

Atom: It is the smallest part of an elementary substance that has the properties of an element. All substances are composed of grouped atoms.

In the atom there are two regions: the nucleus and the electrosphere. The nucleus is made up of two types of atomic particles: protons, which have a positive electrical charge, and neutrons, which have no electrical charge. In the electrosphere are located electrons, particles with a negative electrical charge, which rotate in elliptical orbits around the nucleus.

The negative charges on electrons are attracted to the nucleus, which has a positive charge due to the protons. This attraction compensates for the centrifugal force that tends to pull electrons away from the nucleus. In this way, the electrons keep their movement around the nucleus.

Normally, an atom has the same number of protons and electrons and is therefore electrically neutral. Electrons from the outermost layer of the electrosphere, the valence layer, are attracted to the nucleus with lesser intensity. An external force can cause the atom to lose or gain one or more electrons from that shell, becoming an ion.

An atom can have 1 to 8 electrons in the valence shell. Those that have up to 3 electrons in this shell are more likely to lose electrons. Conductive materials are made up of atoms of this type. In conductor atoms, the valence shell electrons move freely between the atoms of the material, jumping from one atom to another in a disorderly way. These are called free electrons. Due to their presence, these materials easily allow the passage of an electrical current.

As an example of conductors, we can mention metals such as copper, aluminum, gold, and some ionic solutions, such as salts and acids.

Electric quantities

Magnetism: The principle that keeps an atom's electrons rotating around the nucleus is magnetism, whereby charges of the same sign repel and charges of the opposite sign attract.

Electricity: When a positively charged and a negatively charged material are connected by an electrical conductor, free electrons flow from the negatively charged material to the positively charged one. This flow of electrons is called electricity. For a long time it was thought that they actually flow in another way, it was too late to change the publications that existed on electricity. Consequently, for convenience, technical publications have made a commitment to assert that electric current flows from the positive to the negative side, while electrons flow from the negative to the positive side.

Electromagnetism: The term electromagnetism applies to any magnetic phenomenon that takes place in an electric current. When a conductor is traversed by an electric current, there is an orientation in the movement of the particles in its interior. This orientation of the movement of particles has an effect similar to the orientation of molecular magnets. As a result of this orientation, a magnetic field arises around the conductor.

Force Against Electromotive: The counter-electromotive force is an electromotive force that is contrary to or opposed to the main current flowing through a circuit. For example, when the armature coils of an electric motor rotate, a counter-electromotive force is generated in these coils by their interaction with a magnetic field.

Electric tension: Called ΔV, also known as potential difference (DDP) or voltage, it is the difference in electrical potential between two points or the difference in potential electrical energy per unit of electrical charge between two points. Its unit of measure is the volt (named after the Italian physicist Alessandro Volta).

Electric current: It is the ordered flow of particles carrying an electrical charge, or it is also the displacement of charges inside a conductor, when there is a difference in electrical potential between the ends. Such displacement seeks to re-establish the balance that was disrupted by the action of an electric field or other means (chemical reaction, friction, light, etc.).

Electrical resistance: It is the ability of any body to resist the passage of electrical current even when there is an applied potential difference. Its calculation is given by the First Ohm's Law, and, according to the International System of Units (SI), it is measured in ohms.

Electric power: It can be defined as the work performed by the electrical current in a certain period of time. The unit of measure of Power is the Watt; the ratio is defined as: P = U x I (Power = Volts x Current).

Ohm's law

George Simon Ohm was a German physicist who lived between 1789 and 1854 and experimentally verified that there are resistors in which the variation of the electric current is proportional to the variation of the potential difference (ddp). Simon carried out numerous experiments with different types of conductors, applying various voltages to them, however, he realized that in metals, mainly, the relationship between the electric current and the potential difference was always constant. Thus, he elaborated a mathematical relationship that says that the voltage applied to the terminals of a conductor is proportional to the electric current that runs through it, mathematically it is written as follows: V = Ri


V is the potential difference, whose unit is the Volts (V);

I is the electric current, whose unit is the Ampere (A);

R is the electrical resistance, whose unit is the Ohm (Ω).

what is Ohm's law

It is important to note that this law is not always v it does not apply to all resistors, as it depends on what constitutes the resistor. When it is obeyed, the resistor is ohmic or linear. Simon's mathematical expression holds for all types of conductors, both those that obey and those that do not obey Ohm's law. It is clear that the conductor that complies with this law will always have the same resistance value, regardless of the voltage value. And the driver who doesn't obeys, it will have different resistance values for each voltage value applied to it.



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