Voltage - a quantity characterizing the intensity of the electric field inside the conductor. The term seems to contradict the generally accepted, but will be followed by an explanation below.
The electric field in the air
Physicists are not yet able to say that such an electric field. We gathered a lot of knowledge, even made a descriptive formula, expression, but did not really represent. At the same time ridicule the notion of ether, and, therefore, Alessandro Volta, who gave the name is now used to refer to a unit of electric voltage. So, by today's standards:
Electric field - type material by which electrical charges interact.
Readers may have guessed that the rule was discharged from the Soviet textbook (the times of the USSR), it is logical to ask the opinion of "idealists" in the West (in contrast to the materialists). Wikipedia in Russian gives more than careful definition, treating the electric field as a part of the electromagnetic. Without delving into the essence.
As might be expected, in the West say that the electric field - something that eludes the senses, which is determined by a unit test charge by the experience. Definition of a vector field, too little has been reported about the true nature of things. We have to admit that humanity is not yet aware of the field and the reason for their interaction in this way.
Resolved one type of static charges denote positive, the second negative. The existence of two types of recognized more by Benjamin Franklin in the XVIII century. electric field lines begin and end entirely on charges. This is a key postulate explaining the operation of capacitors, displays and other devices. The field is usually denoted by the lines of force emanating from the positive charges and included in the negative. Not all think about the causes of what is happening.
Line directed along said, trial (test) charge (see. definition above) is also positive. The vector is directed along the direction of travel. It is well known that the same sign charges repel, if test positive polarity, it seeks to retire. In the other side and the lines represent the electric field. Accordingly, the trial charge is attracted negative.
Today, the current direction is confused with the true motion of the electrons for the reason that physicists have chosen a positive test charge. Some people believe that Benjamin Franklin misled the entire globe. It is believed that glass has an excess electric liquid (fluid), describing a glass charge. Accordingly, the resin is electricity - negative (excess electrons). Readers may have guessed that at the time of selection were required to do the opposite.
The difference of potentials of electric field
Because of the confusion Earth's magnetic poles (true) are mixed. However, it is mentioned in a subject relevant to the magnetic field. Thus, the tension lines begin on positive charges and end on negative. At each point, characterized by an intensity - the force exerted on a test charge. This value is, of course, vector directed in accordance with the power lines.
As follows from the definition, the unit tension deemed H / C, but in practice, a derivative value - V / m, which is closer to the voltage standing and familiar notation of current and the difference potentials. Empirically, the construction of the field pattern is determined that the field lines do not intersect. This trajectory test (Test) positive (glass) charge. field strength line is not closed on itself for obvious reasons: it turned out the opposite direction to the ends, which is impossible.
From this follows a little-known public fact: at any remoteness of electric charges, the field lines will still find a way. This law is manifested on all planes of the universe. principles of operation of many devices from here occur. For example, the field inside the metal does not exist, the free electrons occupy a position near the surface, that they own tension line block ingress of foreign matter (the term is taken according to the above definition). We agreed that conditionally depicting field force lines in the drawing, through the physics of their size characterize deposition density tension. From the figure becomes clear nature of the distribution of power.
These statements lead to potential. If the field lines do not intersect, begin and end on charges should be indirect, that work is done along each independent of the shape of the trajectory. Similar field of physics called potential:
Employment of an electric field on the charge displacement depends only on the difference between potentials of two points - the initial and final.
There is a potential difference. By this type relates fields and gravitational. Physics Zhdanov and Marandzhyan quite unambiguously interpreted the concept of capacity-building:
Potential energy terms in the field is the work expended field to move a test charge for an infinitely distant away.
This does not mean that the work is accomplished, if the charge is held firmly in place. With the release of the charge would be gradually moved away to infinity. It is clear, a close connection of the magnetic, electric and gravitational fields. From the above definition comes to building:
Potential called potential energy field of a single test charge.
As a rule, it is considered a scalar potential, to make it easier to perform calculations. For definiteness test charge is taken positive, although this is not true. If the work is done against the field forces when moving into an infinite point, the potential is negative. The unit of measurement potential is applied volts.
Voltage is called the potential difference between two points of the field. To distinguish between environment and ether use the term only in the real-life circuits. For example, between the clouds and the ground voltage is present in the hundreds of kW, not directly talking about. Instead, use the term "potential difference" or "tension". It becomes clear definition given above.
When it comes to electrical voltage, imply a certain body. If we talk about broadcasting, operate on the field intensity. This is advantageous in terms of calculations. For example, the amplitude of the signal at the antenna output expressed in terms of intensity, determined by said parameter receiver sensitivity - how weak the field strength the device can be converted into a detailed and clear man signal.
Comparing the units, we note that the number of intensity equal to the voltage divided by the distance between the two points under consideration. This is a common physical formula. Through the expression evaluates the field strength of a plane capacitor. The terms also speak about human representations:
- Stress usually occurs in the material: a subject, a person.
- Tensions observed in relations, not represented directly in the form of matter.
Similarly characterizes the field intensity in the air, and describes voltage conductors and dielectrics. These terms are so scattered on the grounds that the theory does not differ harmony. For example, in the magnetic induction and field intensity introduced, all clear that characterizes the behavior of the first material and dependent upon, and the second is present in absolute terms, in ether. The electric field is poorly described, a rare physicist able to say that is the displacement current in formulas James Clerk Maxwell.
Thus, it is shown that the field intensity is considered the initial value, the electric and magnetic. Voltage - derivative characteristic, through which it is convenient to operate.
influence of voltage
Under the influence of an electrical voltage arises current in conductors as the touch of the external field. two conditions in order to maintain the process:
- Close the contour of the conductors.
- Create a driving force to make up the field of energy.
Dielectrics behave differently. Until then, certain energy field focuses on new small dipoles material. The retaining forces are resilient, permitting the "stocking" in the form of mechanical energy. When the external field is weakened, the system returns to its former state, giving accumulated.
If the voltage is too high, separation occurs dipoles or disbanding. What apparently expressed in fracture of the dielectric material. Then talk about a limiting voltage electrical insulation, above which the agent is unable to perform the functions. It carried 500V electric voltage for conventional, ordinary household dielectric checking circuits
From the history
It is difficult to say who introduced the concept of stress, but in the original form of the term voltage is not mentioned. The English word indicates Alessandro Volta. Physics Electromagnetism era industry becoming increasingly used term electrical tension. It's something to do with the strength of the mechanics. From category as strain gauges floor scales.
By the way, the tension in the West as the intensity (intensity). Alleged founder of Volta because in the writings of all, without exception, scientists beginning of the XIX century slips mot - tension. The modern English word is not.
The answer is simple: it is - a tribute to the tradition established. For example, Alessandro Volta made reports to foreign academies of science, but not armed with an established terminology to go invent the appropriate designation. Introduced into practice the concept of a capacitor (condensor), which stick much better than tension. We believe that the words of Latin origin, and in Italy and Spain, they represent a voltage to this day. Therefore, if the current source takes its name from Luigi Galvani - so said all the authors of the beginning of XIX century - tension going out of the mouth of the Volta.
Unfortunately, the authors did not conduct in-depth study of the question and may not result in the name of work, where it was first performed on the electrical voltage. But it is precisely that Amper, Arago, Ohm operated tension term.
In English, the word voltage hardly appeared before the 80-ies of the XIX century, IEC introduced unit volts only in 1881. It amounted to 100 Mill. GHS voltage units. Subsequently, as epredpolagaetsya, there was a word voltage, replacing the previously present tension.