7 junio, 2024

Dynamic electricity: concept, characteristics, examples

What is dynamic electricity?

The dynamic electricity It consists of the orderly movement of electric charges inside a conductor. It manifests as an electrical current, which can be manipulated to perform a task.

To establish an electric current, a source is necessary to keep the electric charges flowing. This source can be a battery or a generator of some kind.

In addition, the medium in which the charges move must facilitate their displacement, which is why conductive materials, such as metals, are especially suitable.

Metals have one or two electrons loosely bound to the nucleus in their outermost shell, so it is easy for them to move from one atom to another. Normally these movements are random, that is, in any direction, so the net movement is zero.

However, by establishing a potential difference between the ends of the conductor, thanks to a battery, an electric field is created inside the metal, which drives the free electrons towards the positive pole of the battery.

Obviously, the path of the free electrons inside the conductor is not entirely direct, since there are numerous obstacles, such as other particles and existing impurities. This ultimately causes a slow movement, drag or drift of the electrons within the conductor.

It is necessary to emphasize the fact that the electric current is generated by the movement of any charged particle. It’s easy to make electrons flow inside a copper wire, but in general, a set of ions, whether positive or negative, can be set in motion and generate an electrical current.

Characteristics of dynamic electricity

-Dynamic electricity consists of electric charges in motion, and they generate electric current.

-To maintain the flow of loads, an agent is needed to do the necessary work so that they keep moving continuously.

-In the International System of Units, charge is measured in coulombs, abbreviated C, and current in coulombs/second, a unit that receives the name of ampere, which is abbreviated A. A current of 1 A means that times the cross-sectional area 1 C flows from the conductor every second.

-The average current in a conductor is calculated through:

Im = Δq/ Δt

where Δq is the amount of charge that passes through the cross-sectional area in the time interval Δt.

-Electric current always needs a closed path to maintain its flow. This path is called a circuit and it must be closed, because when the current that circulates through it is opened, it stops.

-In principle, the direction of the current is the movement followed by the electrons in the conductor, which leave the negative pole of the battery and go to the positive.

However, by convention, the current is always drawn leaving the positive pole, that is, as if the charge carriers had a positive sign. This is why current is always seen coming out of the + pole in circuit diagrams powered by a direct source.

-Every moving charge produces a magnetic field, so a current-carrying wire always generates one.

current types

Electric current has two variants:

Direct current: It is the one that always flows in the same direction, like the one provided by common batteries.
Alternating current: periodically changes direction and is produced by an alternating current generator. It is also the one obtained at the outlet of domestic outlets.

Examples of dynamic electricity

Electrical circuits

Dynamic electricity is present in the current that circulates in any electrical circuit, however simple it may be. It is needed to turn on lanterns, electric stoves, telephones, and all kinds of household appliances, and it also runs the car’s electrical system.

electricity transmission systems

Electricity transmission systems use dynamic electricity in the form of alternating current, because this is easier to conduct over long distances and with fewer losses, so that it reaches from power plants to homes and streets.

atmospheric electricity

Electric currents are generated in the earth’s atmosphere, which is synonymous with dynamic electricity.

Specifically in the ionosphere, ultraviolet radiation from the Sun causes charged particles that flow in large circuits of electrical current at high altitude.

terrestrial electricity

Numerous electrical currents circulate in the earth’s crust, due to the chemical reactions that take place in the subsoil.

The Earth has its own magnetic field. Inside, the flow of molten iron in the planet’s core generates electrical currents, and these are responsible for creating the Earth’s magnetic field.

polar lights

The auroras (australas or borealis) are regions of the night sky with brilliant and beautiful colors, which appear near the poles.

They are due to dynamic electricity, since a stream of charged particles arrives continuously from the Sun, which is known as solar wind. When these particles approach Earth, the Earth’s magnetic field deflects them, and in doing so, light is emitted, creating the luminous effects of the aurora.

Nervous system functioning

Stimuli from outside reach the senses and the information received travels through the nervous system through electrical impulses to the brain, where they are properly processed. For this, small electrical currents are needed to carry the information.

In the same way, the movement of the muscles depends on electrical impulses that travel from the brain carrying the orders of movement.

defibrillators

Dynamic electricity can severely damage the body, a current of 1 A can be fatal. But used properly, an electric current contributes to saving lives, as in the case of the defibrillator.

A defibrillator is a device that uses large capacitors to send an electrical current to the heart to help it restore its rhythm after a heart attack.

Differences between dynamic electricity and static electricity

-In static electricity, the electric charge accumulates in certain areas of the material, while the dynamics, as it is an electric current, flows through the conductors.

-Rubbing is the main mechanism for the formation of static electricity, while dynamic electricity requires a source that keeps the charges moving. This is achieved through the chemical reactions that occur inside a battery, or through electromechanical alternating current generators, based on Faraday’s law of induction.

-Insulating materials are the main support for static electricity, while electric current needs conductors. This is because, unlike conductors like copper and other metals, insulators lack free electrons. In these, the charge only accumulates, with little chance of circulating.

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