The properties and characteristics of the electric field are studied by almost all technical specialists. But the university course is often written in a complicated and incomprehensible language. Therefore, within the article, the characteristics of electric fields will be available, so that each person can understand them. In addition, we will pay special attention to the interrelated concepts (superposition) and the possibilities for the development of this sphere of physics.
general information
According to modern ideas, electric charges do not interact directly with each other. From this follows an interesting feature. Thus, each charged body has its own electric field in the surrounding space. It affects other subjects. The characteristics of electric fields are of interest to us, that they show the effect of the field on electric charges and the force with which it is carried out. Which of this can be inferred? Charged bodies do not have mutual direct effects. Electric fields are used for this. How can they be investigated? To do this, you can use a test charge - a small point beam of particles, which will not have a noticeable effect on the existing structure. So what are the characteristics of the electric field? There are only three of them: tension, tension and potential. Each of them has its own features and spheres of influence on particles.
Electric field: what is it?
But before proceeding to the main subject of the article, it is necessary to have a certain amount of knowledge. If they are, then this part can be confidently skipped. Initially, let us consider the cause of the existence of an electric field. In order for it to be, you need a charge. Moreover, the properties of the space in which the charged body resides must be different from those where it does not exist. Here there is such a feature: if you place a charge in a certain coordinate system, the changes will occur not instantaneously, but only at a certain speed. They will, like waves, spread in space. This will be accompanied by the appearance of mechanical forces that act on other carriers in this coordinate system. And here we come to the main thing! Emerging forces are the result of not direct influence, but interaction through the environment, which has changed qualitatively. The space in which these changes occur is called the electric field.
Features
A charge located in an electric field moves in the direction of the force, which acts on it. Is it possible to achieve a state of rest? Yes, it is quite real. But for this, the strength of the electric field must balance some other influence. As soon as there is an imbalance, the charge starts moving again. The direction in this case will depend on greater strength. Although if there are many of them, the final result will be something balanced and universal. To better represent what has to be done, the lines of force are depicted. Their directions correspond to the acting forces. It should be noted that the lines of force have both a beginning and an end. In other words, they do not shut themselves up. They begin on positively charged bodies, but end in negative ones. This is not all, we will talk in more detail about the lines of force, their theoretical underpinnings and practical implementation, a little further on in the text and consider them together with the Coulomb law.
Electric field strength
This characteristic is used to quantify the electric field. This is quite difficult to understand. This characteristic of the electric field (tension) is a physical quantity equal to the ratio of the force of action to the positive test charge, which is located at a certain point in space, to its magnitude. There is one special aspect. This physical quantity is vector. Its direction coincides with the direction of the force, which acts on the positive test charge. One should also answer one very common question and note that it is tension that is the power characteristic of the electric field. And what happens to immovable and unchanging subjects? Their electric field is considered electrostatic. Interest in the point charge and the investigation of tension is provided by the lines of force and the Coulomb law. What features are there?
Coulomb law and lines of force
The power characteristic of the electric field in this case works only for a point charge, which is at a distance of a certain radius from it. And if we take this value modulo, then we will have a Coulomb field. In it, the direction of the vector depends directly on the sign of the charge. So, if it is a plus, then the field will "move" along the radius. In the opposite situation, the vector will be directed directly to the charge itself. For a visual understanding of what and how it happens, you can find and read the drawings, where the lines of force are depicted. The main characteristics of the electric field in textbooks, although difficult to explain, but the drawings, they should be given credit, they are quality. True, it should be noted such a feature of books: when constructing drawings of lines of force, their density is proportional to the modulus of the tension vector. This is a small clue that can be of great help in controlling knowledge or exams.
Potential
The charge always moves when there is no balance of forces. This tells us that in this case the electric field has potential energy. In other words, it can do some work. Let's look at a small example. The electric field moved the charge from point A to B. As a result, the potential energy of the field is reduced. This is due to the fact that the work was done. This force characteristic of the electric field will not change if the movement was made under a side effect. In this case, the potential energy will not decrease, but increase. And this physical characteristic of the electric field will change in direct proportion to the applied external force, which moved the charge in the electric field. It should be noted that in this case all the work done will be spent on increasing the potential energy. To understand the topic, let's take a look at the following example. So, we have a positive charge. It is located outside the electric field, which is considered. Due to this, the impact is so small that it can be ignored. There is an external force that brings a charge into the electric field. She does the work necessary to move. At the same time, the forces of the field are overcome. Thus, the potential of actions arises , but already in the electric field itself. It should be noted that this may be a non-uniform indicator. So, the energy, which relates to each particular unit of positive charge, is called the field potential at this point. It is numerically equal to the work that was done by a third party force to move the subject to a given place. The potential of the field is measured in volts.
Voltage
In any electric field, one can observe how positive charges "migrate" from points with high potential to those that have low parameters of this parameter. Negatives follow this path in the opposite direction. But in both cases this happens only because of the potential energy. From it, the voltage is calculated. To do this, it is necessary to know the value to which the potential energy of the field has become smaller. The voltage is numerically equal to the work that was done to transfer the positive charge between two specific points. From this one can note an interesting correspondence. So, voltage and potential difference in this case are the same physical entity.
Superposition of electric fields
So, we considered the main characteristics of the electric field. But in order to better understand the topic, we propose to additionally consider a number of other parameters that may be important. And we will start with a superposition of electric fields. Previously, we considered situations where, by condition, there was only one particular charge. But there are a lot of them in the fields! Therefore, considering the situation approached to reality, let's imagine that we have several charges. Then it turns out that the trial subject will act forces that are subject to the rule of addition of vectors. Also, the principle of superposition suggests that complex motion can be divided into two or more simple ones. It is impossible to develop a realistic model of motion without taking superposition into account. In other words, the particle under consideration under the existing conditions is affected by various charges, each of which has its own electric field.
Using
It should be noted that now the potential of the electric field is not being used to its full potential. Even more correctly, we almost do not apply its potential. As a practical realization of the possibilities of an electric field, one can bring Chizhevsky's chandelier. Earlier, in the middle of the last century, mankind began to explore space. But before the scientists there were many unresolved issues. One of them is air and its harmful components. For solving this problem, the Soviet scientist Chizhevsky, who was simultaneously interested in the energy characteristic of the electric field, took up the problem. And it should be noted that he had a really good development. The device was based on the technique of creating aeroionic air flows due to small discharges. But within the framework of the article, we are interested not so much in the device itself as in the principle of its operation. The point is that Chizhevsky's chandelier was used not for a stationary power source, but for an electric field! To concentrate the energy, special capacitors were used. Significantly, the success of the device was influenced by the energy characteristics of the electric field of the surrounding environment. That is, this device was designed specifically for spacecraft, which are literally stuffed with electronics. It also fed on the performance of other devices connected to permanent power supplies. It should be noted that the direction was not abandoned, and the possibility to take energy from the electric field is being investigated now. True, it should be noted that significant progress has not yet been made. It is also necessary to note the relatively small scale of the research conducted, and the fact that most of them are performed by inventors-volunteers.
What are the characteristics of the electric fields?
Why do we need to study them? As mentioned before, the characteristics of the electric field are tension, voltage and potential. In the life of ordinary ordinary people, these parameters can not boast a significant influence. But when there are questions about what should be done something big and complex, then do not take them into account - inadmissible luxury. The fact is that the excessive number of electronic fields (or their excessive force) leads to the fact that there is interference in the transmission of signals by technology. This leads to distortion of the transmitted information. It should be noted that this is not the only problem of this type. In addition to the white noise of technology, excessively strong electronic fields can adversely affect the work of the human body. It should be noted that a small ionization of the room is still considered a boon, since it contributes to the settling of dust on the surfaces of the human dwelling. But if you look at how many different techniques (refrigerators, televisions, boilers, telephones, electricity systems, etc.) are in our homes, then we can conclude that this, alas, is not useful for our health. It should be noted that the low characteristics of electric fields are almost not harmful to us, since humanity has long been accustomed to cosmic radiation. But it's so hard to say about electronics. Of course, you will not be able to give up all this, but you can successfully minimize the negative impact of electric fields on the human body. For this, incidentally, it is sufficient to apply the principles of energetically effective use of technology, which involves minimizing the operating time of the mechanisms.
Conclusion
We examined what physical quantity is a characteristic of an electric field, where it is used, what is the potential of development and application of them in everyday life. But still want to add a few final words about the topic. It should be noted that they were interested in a fairly large number of people. One of the most notable traces in history was the famous Serbian inventor Nikolai Tesla. He managed to achieve considerable success in this respect with regard to the implementation of the plan, but, alas, not in terms of energy efficiency. Therefore, if there is a desire to work in this direction, there are many undiscovered possibilities.