In this article we will consider that this is a conductor. Here questions of its definition, features and properties will be touched upon. We will also dwell on the concept of the potential of a conductor. The object under study is an important discovery and achievement of science, which allows a person at the present stage of development to reduce the cost of consuming important and exhaustible resources of the earth.
Introduction
A conductor is primarily a substance, as well as a certain medium or material, that conducts an electric current with little or no obstruction. Conductors contain a large number of freely moving charge carriers (particles with a charge), which are able to move freely inside the conductors. These carriers are influenced by the conductor, which is close to the object of electric voltage and create a conduction current.
There is a concept of a homogeneous conductor. It's a set of characteristics that are the sameat any point. An example is a reochord - a device for measuring email. resistance using the Wheatstone bridge method.
Due to the presence of a large number of free charge carriers and a high degree of their mobility, the value of the specific quantity that determines the electrical conductivity reaches large values. From the point of view of electrodynamic science, a conductor is a medium with a huge value of tangent, indicating the angle of dielectric loss. Consideration always takes place through the determination of a clear frequency. An ideal conductor in this case is a material that has a value of tgδ in an infinitely large size. All other types of such structures are called real, or lossy.
Part of an electrical circuit
A conductor is part of an electrical circuit (connecting wire, metal bus, etc.).
One of the most common conductive solid-type structures are substances of metals, semimetals and carbons (graphite and coal). Examples of conductive liquids include mercury, electrolytic solutions, and metal melts. Among gases capable of conducting current, the most prominent representative is gas in ionized form (plasma). Some substances, more often semiconductors, can change their conductive properties if the external conditions around them change, such as raising the temperature or doping.
Electrical conductors are substances and materials that, in accordance with the form of movementparticles are divided into the first and second kind. In the first case, the property of conductivity is determined by electronic motion, and in the second, by ionic motion.
Current in conductor
Under the electric current means the movement of particles with a charge, in an orderly manner. Current can be generated in a variety of environments. A prerequisite is the presence of mobile charge carriers that can move under the influence of a field that is applied from the outside.
Current is a scalar value that can take two values: positive and negative. It depends on the arbitrary direction along which the particles move. The unit of current is the ampere (A).
The strength of the current in the conductor is a quantity that can be determined by the direction of the positively charged elements that form the current. In the case when the current was due to particles with a charge of "-", it acquires a direction opposite to the course of the real speed of the particles.
The current strength is determined by analyzing the ratio Dq (amount of charge) that was transferred through the conductor cross section, per unit time Dt, to the dimensional value of the interval itself:
I=Delta q/ Dela t.
The concept of drift
The indicator indicating the strength of the current is closely related to the charge drift phenomenon. particles. Suppose we have a conductor, in the section of the cross section (S) of which, there is a certain number of charge carriers in a specific volume corresponding to the number - n. Charge all carrierscorresponds to the value q0. If you apply an external electr. field (E), then the carriers will acquire an average velocity v (a measure of the drift velocity), which is directed towards the opposite field. If we assume that the drift has a constant speed (the current moves at the same pace and with the same power), we can calculate the strength of the relationship between the drift and the movement of particles:
∆q=q0nv∆ts, which implies that I=q0nvS
The total amount of charge in the total volume of the cylinder with the value of the generatrix Dl=vDt is.
Resistance Phenomenon
The electrical resistance of a conductor is a value that characterizes its properties that can prevent the flow of current, and it is also equal to the ratio of the voltage at the end sections of the wire to the strength of the current that is passed.
The concept of impedance and the phenomenon of resistance waveform describe the reaction for a current circuit with variable values, as well as electromagnetic fields. In this case, the concept of a resistor means a radio component, the purpose of which is to introduce active resistance into an electr. chain.
The resistance of a conductor is a value that is most often denoted by the letter R (small or large). Within certain limits, it is constant and is calculated by the formula:
R=U/I, where R is the amount of resistance, I indicates the strength of the current that flows between the different ends of the conductor under the influence of the potential difference (A), and U is the degreeelectrical difference. potentials that are located on its opposite sides.
Physical aspect of the phenomenon
Electric current in a conductor is an ordered movement of particles with a certain charge. Metals have high electrical conductivity, which is due to the presence of a huge number of electron carriers. current (conduction electrons), which are formed from the valence series of electrons of metals. The latter should not belong to a certain kind of atoms.
The electrons that move due to the action of the field begin to scatter on the inhomogeneity of the ionic lattices. The electron itself in this case loses its momentum, and the energy responsible for the movement is converted into the internal energy of the lattice of a crystalline nature. It causes heating of the conductor due to the passage of email. current through it. It is important to remember that the meaning of a linear relationship, which is expressed by Ohm's law, is not always respected. The magnitude of the resistance is also determined by the features of its geometry and the properties of the specific email. resistance of the material from which it was formed.
Section of conductor
The cross section of a conductor is a characteristic closely related to the phenomenon of its resistance. The fact is that the charge carrier in the metal is a free electron. Being in a chaotic form of movement, they are like gas molecules. For this reason, classical physics defines electrons in a metal as an electron gas. Applicable herelegal provisions for ideal gases.
Indicator of the density of el. gas and the structure of crystal lattices are due to the type of metal. For this reason, the resistance depends on the kind of substance itself from which the conductor was created. Its length, temperature and cross-sectional area are also taken into account. The influence of the latter can be explained due to the fact that a decrease in the cross section of the electron flow inside the conductor, with the same value of the current strength, leads to a compaction of the flow. This causes an increase in the interaction between the electron and the particle of the conductor substance.
Potential
The electrical potential of a conductor is a special characteristic of a conductor, presented as a scalar energy parameter of potential energy, which is “filled” with a positively charged unit version of the test charge, which was placed at a specific point on the field. To measure this value, the International System of Units (SI) is used, namely the Volt (1V=1J / C). The electric potential is equal to the ratio of the magnitude of the potential energy, indicating the interaction of the charge and the field, to the dimension of the charge itself.
