Electrical Load Example

The Electric charge it is a force possessing a subatomic particle, either a proton, neutron or electron, and that influences another proton, neutron or electron, either by attracting it or repelling it.

Modern atomic theory of matter holds that all substances are made up of atoms and molecules. Atoms are made up of elementary particles called electrons, protons, and neutrons.

In the center of the atom is the nucleus and that is where the protons whose electric charge is positive (+) and the neutrons with zero electric charge are located. The electrons are rotating around the nucleus and have a negative electrical charge (-).

When an atom loses electrons it is left with a positive charge. If it gains electrons, it is negatively charged.

An atom of matter is in a neutral or uncharged state because it contains the same number of protons in its nucleus as electrons around it.

The ability that bodies acquire to attract other objects after being rubbed with a wool or silk garment is known as "carrying."

When two different substances or bodies rub against each other, one of them loses electrons, remaining with a negative electrical charge, such is the case of rubbing the hair with a comb or a balloon; the hair loses electrons and the comb gains them, the electrical charge produced by this imbalance is called static electricity or we say that the hair becomes electrified; This example allows a better understanding of the Law of Conservation of Charge, which says:

"The total Electric Charge of the Universe is a constant magnitude, it is neither created nor destroyed"

When a body is electrified by friction, the charge is not created, since it has always been there, nor are new electrons produced, they only pass from one body to another.

The electrification of bodies can be verified through phenomena that are observed daily, for example when a metallic object is touched an electric touch is felt, this is because the object is electrically charged and when you touch it, the electrical charge goes to ground through the object itself Body.

Interaction between electrical charges

When bodies are electrified, they acquire electrical charges that can be of two types: positive or negative, depending on the material the bodies are made of. To verify this, the Electric Pendulum experiment is carried out. An electric pendulum is a sphere of Styrofoam or cork hung by means of a thread to some support.

If a plastic rod is rubbed with a piece of wool and the rod is brought close to the styrofoam sphere of the pendulum, the rod will attract the sphere; after being in contact with the rod for a moment, the sphere will be repelled by the rod.

Part of the charge has been transferred from the bar to the sphere and the two objects are charged in the same way.

If the same experiment is done, but instead of the plastic rod a glass rod is used and rubbed with a piece of silk, the same results will be observed.

But if the sphere of the electric pendulum is charged with the plastic rod and another sphere of another electric pendulum with the rod glass and both Styrofoam spheres approach, it is observed that there is an attraction between them, so it can be concluded what the electrical charges produced by the plastic and glass bars are opposite.

It has been shown that all electrified materials can be divided into two groups: those with a load such as that produced by the glass rod and those with a load such as that produced by the glass rod plastic. By convention it was established that those that behave like the first group have a positive charge (+) and those that behave like the second group have a negative charge (-) and based on this it can be stated the "First Law of Electrostatics":

"Charges of the same sign repel and charges of the opposite sign attract"

Units of measurement of electric charge

In the International System of Units, which is the most practical system for the study of electricity, the unit of Charge is expressed in Coulombs (C).

By Definition: A Coulomb is the charge transferred in one second through any cross section of a conductor, by a constant current of one Ampere (1 A).

Comparing the charge of 1 Coulomb with the charge of an electron, we have:

1 C = 6.25 x 10⁸ electrons

The charge of an electron expressed in Coulombs is:

1 e = -1.6 x 10^-19 C

Another unit of measurement for charges is the microCoulomb (μC), and its equivalence in Coulombs is:

1 μC = 1 x 10^-6 C

Examples of Electrical Charge

The one produced by rubbing between a glass rod and a silk cloth

The one produced by rubbing a plastic bar with a piece of wool

The one that happens when passing a comb through the hair

The one that occurs when a balloon is rubbed against the hair

When taking off a sweater, there is a jump of electrons. Seen in the dark, sparks are detected

When a hand is placed on an electrified metal surface, electrons flow into the skin.

A charged balloon sticks to the wall. The electrons jump toward the wall, and the balloon falls off when the exchange is over.

If a PVC tube is rubbed with a cloth, electrons will remain floating in the tube.

Styrofoam spheres also adhere to loaded PVC pipes.

Confetti and finely divided paper are attracted to charged surfaces and are even difficult to remove.