We explain what voltage is and the types that exist. Also, what Ohm's Law consists of and how this magnitude is measured.
What is voltage?
Voltage is the magnitude that accounts for the difference in electrical potential between two given points. Also called electric potential difference either electrical voltage, is the work per unit of electric charge exerted on a particle by an electric field to be able to move it between two specific points.
When two points that have a difference in electrical potential are joined with a conductive material, a flow of electrons will occur, known as electric current, which will carry part of the charge from the point of highest potential to that of lowest potential.
This difference in electrical potential is the voltage, and said current will cease as soon as both points have the same potential, unless a certain potential difference is maintained by a generator or an external source of some type.
Thus, when talking about the voltage of a single point, it is referred to in comparison with any other body with which it comes into contact and whose potential is assumed equal to zero.
To understand voltage, a hydraulic metaphor (with water) is often used. Let's imagine a circular route of pipes through which water circulates (equivalent in this case to the flow of electrons). The wide pipes will be conductive materials, the narrow ones will be insulators or resistors. This path will be mobilized by a hydraulic pump (which for the example, is equivalent to the voltage source) pushing the water based on a pressure difference with respect to another point in the pipe. This pressure difference is equivalent to electrical voltage.
In conclusion, a circuit equipped with high voltage will have a greater work capacity (the water moves with greater force, in the previous example) and therefore will be more powerful or even more dangerous.
Voltage types
There are the following types of voltage:
- Induced voltage This is the name given to the electromotive force or induced voltage necessary to generate electrical energy within a circuit, that is, to generate a potential difference. In an open circuit, this force can maintain electrical tension between two points, in a closed circuit, it will generate a flow of current.
- Alternating voltage It is represented by the letters VA, with positive and negative values on a Cartesian axis, since it is considered a sine wave. It is the most common voltage in electrical outlets because it is the easiest to generate and transport. As its name indicates, it is a voltage with alternating values, not constant over time and its frequency will depend on the country or specific region.
- Direct current voltage It is common in motors and batteries, and is obtained from the transformation of alternating current into more or less direct current, with small peaks, using fuses and transformers.
- Continuous voltage Also called direct current voltage (VCC), it is the purest current there is, present in chips, microprocessors and other devices that require continuous and constant voltages. It is usually obtained after treatment with electrolytic capacitors.
Ohm's Law
Postulated by the German physicist Georg Simon Ohm, it dictates that the potential difference (V) applied between the ends of a specific conductor will be proportional to the amount of current (I) flowing through the conductor, depending on its resistance. This was expressed in the following formula:
V = R. Yo where V is the tension, Yo is the current and R the resistance of the material.
Having any two of these variables, it is possible to calculate the third easily.
How is voltage measured?
A voltmeter is used to measure voltage which is installed parallel to the energy source to measure and quantify the electrical potential. Other devices used are the tester (or multimeter) and the potentiometer.
In any case, the voltage is calculated taking into account the total energy necessary to move a small electrical charge from the beginning to the end of the circuit, divided by the magnitude of said charge.
According to the International System (SI), Electrical voltage is measured in volts (hence the term voltage), represented by the letter V, in honor of Alejandro Volta, creator of the voltaic cell in the 17th century. One volt is equal to one July divided by a Coulomb.
