The dynamic power, better known as electric current corresponds to the flow of electrons through a conductor of electricity. Generally this flow originates due to a difference in electrical potential. Power sources can be chemical (batteries) and electromechanical (eg hydraulic generators).
The conductors can be solid, liquid or gaseous, since the movement of electrons occurs through any medium, depending on the resistance it has with respect to electrical conductivity.
How is it produced?
Without a doubt, the fact that electric current is associated with dynamism implies movement. Hence, this phenomenon is studied through the branch of physics called electrodynamics.
As previously mentioned, the movement of electrons is due to the difference in voltage (voltage) between two points, which must be linked by an electrically conductive material.
This results in the presence of an electric field that, in turn, induces the flow of electricity through the system.
For electrons to mobilize, they must leave the nucleus of an atom with a balanced electric charge, it is there when a free electron is generated. These are called particles of mobile charge and are what make the flow of electricity possible under the action of an electric field.
The electric field can occur thanks to electro-mechanical, thermoelectric, hydraulic generation mechanisms or electrochemical cells, such as batteries for vehicles, among others.
Regardless of the electrical energy generating process, each mechanism outputs a potential difference at its ends. In the case of direct current (eg chemical batteries), the battery outputs have a positive and a negative terminal.
When both ends are connected to a conductive circuit, the electric current circulates through it, giving way to dynamic electricity.
Types
Depending on the nature of it and the characteristics of circulation, dynamic electricity can be continuous or direct. Here is a brief description of each type of dynamic electricity:
DC
This type of current circulates in a single direction, without any type of fluctuations or disturbances in its flow.
If the path it makes over time is plotted, a perfectly horizontal straight line will be seen, provided that the voltage level (voltage) remains constant over time.
In this type of dynamic electricity the electric current always circulates in the same direction; that is, the positive and negative terminals retain their polarity at all times, they never alternate.
One of the major disadvantages of direct current, known as DC for its acronym in English (direct current), is the low resistance of the conductors when transmitting electrical power with high voltage levels and over long distances.
The heating that occurs in the conductors through which the direct current circulates implies significant energy losses, thus making direct current inefficient in this class of processes.
Alternating current
This type of current circulates in two alternate directions, just as the name implies. During one half cycle the current has a positive sign, and during the remaining half cycle it has a negative sign.
The graphical representation of this type of current with respect to time reflects a sinusoidal curve, whose movement varies periodically.
In alternating current, popularly known as AC for its acronym in English (alternating current), the direction of circulation of the electrons changes in each half cycle.
Currently, alternating current is used in the generation, transmission and distribution of electricity worldwide, thanks to its high levels of efficiency in the energy transport process.
In addition, voltage transformers allow the voltage of the transmission system to be raised and lowered quickly, which helps to optimize technical losses due to heating of the conductors during the process.
Real examples
Dynamic electricity, both in the form of direct current and in the form of alternating current, is present in our lives in various daily applications. Some palpable examples of dynamic electricity in everyday life are:
- Electric generators that supply electricity to large cities, either through hydroelectric or wind turbines, thermoelectric plants, and even solar panels, among other mechanisms.
- Outlets for domestic use, through which electrical appliances and other household utensils that require electricity are powered, are the local electricity supplier for residential use.
- Vehicle or cell phone batteries, as well as domestic batteries for portable electrical appliances. All of these work with electrochemical arrangements that induce the circulation of DC current by joining the ends of the device.
- Electrified fences, also known as electric fences, work from the discharge of direct current, which expels the person, animal or object that makes direct contact with the fence.
Do you have health risks?
Electric current has multiple risks to human health, as it can cause severe burns and lacerations, and can even kill an individual depending on the intensity of the shock.
To evaluate the effects of the circulation of electric current through the body, two basic factors must be considered: the intensity of the current and the time of exposure to it.
For example: if a current of 100 mA flows through the heart of an average person for half a second, there is a high probability that ventricular fibrillation will occur; that is, the heart begins to tremble.
In this case, the heart stops pumping blood to the body on a regular basis, since the natural movements of the heart (systole and diastole) do not occur and the circulatory system is severely affected.
In addition, when faced with an electric shock, muscle contractions are triggered that produce untimely movements in the body of those affected. Consequently, people are vulnerable to falls and serious injuries.
References
- Canadian Center for Occupational Health and Safety (2018). Electrical Safety - Basic Information. Recovered from: ccohs.ca
- Dynamic Electricity (sf). Recovered from: vidyut-shaastra.com
- Electrical risks (2017). Australian Government Comcare. Recovered from: comcare.gov.au
- Electricity (2016). Recovered by: meanings.com
- Platt, J. (2013). Electrical safety: How electrical current affects the human body. Recovered from: mnn.com
- what is electricity? (sf). Recovered from: fisicalab.com
- Wikipedia, The Free Encyclopedia (2018). Electric current. Recovered from: es.wikipedia.org