We explain what voltage is and the types that exist. Also, what is Ohm's Law and how is this magnitude measured?
What is voltage?
Voltage is the magnitude that accounts for the difference in electric potential between two determined points. Also called electric potential difference or electric tension, is the work per unit of electric charge which exerts on a particle a electric field, to be able to move it between two determined points.
When two points that present a difference in electric potential are joined with a conductive material, a flow ofelectrons, which is known as electric current, which will carry part of the load from the point of highest to the lowest potential.
Said electric potential difference is the voltage, and saidcurrent it 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 kind.
Thus, when talking about single point voltage, 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 is often used (with Water). Let's imagine a circular route of pipes through which the water circulates (equivalent in this case to the flow of electrons). The wide pipes will be conductive materials, the narrow ones will be insulating or resistances. 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 pipeline. This difference of Pressure it is equivalent to electrical voltage.
In conclusion, a circuit equipped with high voltage will have a greater working capacity (the water moves with greater force, in the previous example) and therefore it 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 electrmotive force or induced voltage necessary to generateelectric power within a circuit, that is, to generate a potential difference. In an open circuit, this force can maintain the electrical voltage between two points, in a closed circuit, it will generate a current flow.
- 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 power outlets because it is the easiest to generate and transport. As its name implies, it is a voltage with alternating values, not constant in the weather and its frequency will depend on the country or specific region.
- Direct current voltage. It is usual in engines andbatteries, and is obtained from the transformation of alternating current into more or less continuous current, with small peaks, using fuses and transformers.
- Continuous voltage Also called voltage ofDC (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 applied potential difference (V) between the ends of a specific conductor will be proportional to the amount of current (I) flowing through the conductor, depending on its endurance. This was embodied in the following formula:
V = R. I, where V is the tension, I is the current and R the strength of the material.
Having any two of these variables, it is possible to calculate the third with ease.
How is voltage measured?
A voltmeter is used to measure the voltage, which is installed parallel to the power source. Energy to measure and quantify the electric potential. Other devices used are the tester (or multimeter) and potentiometer.
Either way, the voltage is calculated taking into account the total energy required to move a small electrical charge from the beginning to the end of the circuit, divided by the magnitude of that charge.
According to International system (SI), the electrical voltage is measured in volts (hence the termvoltage), represented by the letter V, in honor of Alexander Volta, creator of the voltaic pile in the 17th century. One volt equals one July divided by a Coulomb.