In this article we will consider that it is a vehicle. Here questions of its definition, features and properties will be raised. We also dwell on the concept of the potential of the conductor. The object under study represents 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 land resources.
Introduction
A conductor is primarily a substance, as well as a specific medium or material that conducts an electric current with virtually no obstruction. In the conductors is a large number of freely moving charge carriers (particles with a charge), which are able to freely move inside the conductors. These carriers are influenced by the conductor, which is close to the object of electrical voltage and create a conduction current.
There is the concept of a homogeneous conductor. This is a set of characteristics that are the same at any point. An example is reochord - a device for measuring electronic. resistance through 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 value determining the electrical conductivity reaches large values. From the point of view of electrodynamic science, a conductor is a medium with a huge tangent value, indicating the dielectric loss angle. Consideration always takes place by defining a clear frequency. The ideal conductor in this case is a material with an infinitely large size tanδ. All other types of such structures are called real, or with loss.
Electric circuit part
A conductor is part of an electrical circuit (connecting wire, metal bus, etc.).
One of the most common conductive structures of the solid type are substances of metals, semimetals and carbons (graphite and coal). Among conductive fluids, mercury, electrolytic solutions, and metal melts are examples. Among the gases capable of conducting current, the brightest representative is the gas in ionized form (plasma). Some substances, most often semiconductors, can change their conductivity properties if they change the external conditions around them, for example, increase the temperature or dope.
Electrical conductors are substances and materials that, in accordance with the form of particle motion, are divided into the first and second kind. In the first case, the conductivity property is determined by electronic motion, and in the second, by ionic motion.
Conductor current
By electric current is meant the movement of particles having a charge in an ordered form. Current can form 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.
The current strength is called a scalar quantity, which can take two values: positive and negative. It depends on the arbitrary direction along which the particles move. The unit determining the current strength is ampere (A).
The current strength in the conductor is a value 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 movement 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 dimension value of the interval itself:
I = Delta q / Dela t.
Drift concept
An indicator indicating the strength of the current is closely related to the phenomenon of charge drift. particles. Suppose we have a conductor, in the cross-section (S) of which there is a certain number of charge carriers in a specific volume, corresponding to the number - n. The charge of all carriers corresponds to q0. If you attach an external electric. field (E), then the carriers will acquire the average value of velocity v (an indicator 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 = q 0 nv∆ts, from which it follows that I = q 0 nvS
The total charge in the total volume of the cylinder with the value of the generating quantity Dl = vDt is equal.
Phenomenon of resistance
The electrical resistance of a conductor is a value that characterizes its properties that can prevent the passage of current, and it is equal to the ratio of the voltage at the end sections of the wire to the current strength that is passed.
The concept of impedance and the phenomenon of the waveform of resistance describe the reaction for a current circuit with variable values, as well as electromagnetic fields. In this case, the term resistor is understood to mean a radio component, the purpose of which is to introduce active resistance into an electron. chain.
The resistance of the conductor is the value that is most often denoted by the letter R (small or large). In some limits, it is constant and is calculated by the formula:
R = U / I,
where R is the resistance value, I - indicates the current strength that flows between the different ends of the conductor under the influence of the potential difference (A), and U is the degree of difference of the electron. potentials that are located on its different sides.
The physical aspect of the phenomenon
An electric current in a conductor is an ordered movement of particles with a certain charge. Metals have high electrical conductivity, which is associated with the presence of a huge number of electronic carriers. current (conduction electrons), which are formed from a valence row of metal electrons. The latter should not belong to a certain type of atom.
Electrons that move due to the field begin to scatter on the inhomogeneities of the ionic lattices. In this case, the electron itself loses the momentum, and the energy responsible for the motion turns into the internal energy of the crystal lattice. It causes heating of the conductor due to the passage of el. current over it. It is important to remember that the value of the linear relationship, which is expressed by Ohm's law, is not always respected. The resistance value is also determined by the features of its geometry and the properties of specific electric. resistance of the material from which it was formed.
Conductor cross section
The cross section of the conductor is a characteristic closely related to the phenomenon of its resistance. The fact is that a charge electron in a metal is a free electron. Being in a chaotic form of motion, they are similar to gas molecules. For this reason, classical physics defines electrons in a metal as electron gas. The legal provisions for ideal gases apply here.
Density Index gas and the structure of the crystal lattices are due to the nature of the metal. For this reason, the resistance depends on the kind of substance itself from which the conductor was created. It also takes into account its length, temperature and cross-sectional area. The influence of the latter can be explained due to the fact that a decrease in the cross section of the electron flux inside the conductor, with the same current value, leads to compaction of the flux. This causes an increase in the interaction between the electron and the particle of the conductor substance.
Potential
The electric potential of a conductor is a special characteristic of a conductor, presented in the form of a scalar energy parameter of potential energy, with which a positively charged single version of the test charge is “filled”, which was placed at a specific point on the field. To measure this value, use the International System of Units (SI), namely the Volt (1V = 1J / C). The electric potential is equal to the ratio of the potential energy, indicating the interaction of the charge and the field to the dimension of the charge itself.