The properties and characteristics of the electric field are studied by almost all technical specialists. But a university course is often written in a complex and incomprehensible language. Therefore, within the framework of the article, the characteristics of electric fields will be described in an accessible way, so that everyone can understand them. In addition, we will pay special attention to the interrelated concepts (superposition) and the development possibilities of this sphere of physics.
general information
According to modern concepts,
electric charges do not interact directly with each other. An interesting feature follows from this. So, 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 in that they show the effect of the field on electric charges and the force with which it is carried out. Which of these can be concluded? Charged bodies do not have a mutual direct effect. For this, electric fields are used. How can they be researched? 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 three of them:
tension, tension and potential. Each of them has its own characteristics and spheres of influence on particles.
Electric field: what is it?
But before moving on to the main subject of the article, you need to have a certain amount of knowledge. If they are, then this part can be safely skipped. First, let's look at the cause of the existence of an electric field. In order for it to be, a charge is needed. Moreover, the properties of the space in which the charged body resides should be different from those where it does not exist. Here there is such a feature: if a charge is placed in a certain coordinate system, then changes will not occur instantly, 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! The forces that arise are not the result of direct influence, but of interaction through an environment that has changed qualitatively. The space in which such changes take place is called the electric field.
Features
A charge located in an electric field moves in the direction of the force that acts on it. Is it possible to achieve a state of rest? Yes, that’s quite real. But for this, the strength of the electric field must balance some other influence. As soon as an imbalance occurs, the charge begins to move again. The direction in this case will depend on more power. Although if there are a lot of them, the end result will be something balanced and universal. To better understand what you have to work with, they draw lines of force. 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 lock on themselves. They begin on positively charged bodies, and end on negative ones. This is not all, in more detail about the lines of force, their theoretical background and practical implementation, we will talk a little further in the text and consider them together with the Coulomb law.
Electric field strength
This characteristic is used to quantify the electric field. It is quite difficult to understand. This characteristic of the electric field (intensity) 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 value. There is one particular aspect. This physical quantity is vectorial. Its direction coincides with the direction of the force that acts on the positive test charge. You should also answer one very common question and note that the strength characteristic of the electric field is precisely the intensity. And what happens to fixed and unchanging subjects? Their electric field is considered electrostatic. When working with a point charge and investigating tension, the lines of force and Coulomb's law are of interest. What features exist here?
Coulomb law and lines of force
The force 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 on the sign of the charge. So, if it is positive, then the field will “move” along the radius. In the opposite situation, the vector will be directed directly to the charge itself. For a clear understanding of what is happening and how, you can find and familiarize yourself with the drawings, which depict the lines of force. The basic characteristics of the electric field in textbooks, although it’s rather difficult to explain, but the drawings should be given their due, they are of high quality. The truth should be noted such a feature of books: when building drawings of lines of force, their density is proportional to the modulus of the tension vector. This is a small tip that can be very helpful in controlling your knowledge or exam.
Potential
The charge always moves when there is no balance of power. 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 has moved the charge from point A to B. As a result, a decrease in the potential energy of the field is observed. This is due to the fact that work has been completed. This force characteristic of the electric field will not change if the movement was made under external influence. In this case, the
potential energy will not decrease, but increase. Moreover, this physical characteristic of the electric field will change in direct proportion to the applied external force, which will move 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 look at the following example. So, we have a positive charge. It is located outside the electric field that is being considered. Due to this, the effect is so small that it can be ignored. An external force arises, which introduces a charge into the electric field. She does the work necessary to move. In this case, the field forces are overcome. Thus, the
potential of action arises
, but already in the electric field itself. It should be noted that this may be a heterogeneous indicator. So, the energy that relates to each specific unit of a positive charge is called the field potential at this point. It is numerically equal to the work that was performed by an outside force to move the subject to a given place. Field potential 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. Negative follow this path in the opposite direction. But in both cases, this happens only due to the presence of potential energy. The voltage is calculated from it. For this, it is necessary to know the value by which the potential field energy has become smaller. The voltage is numerically equal to the work that was done to transfer a positive charge between two specific points. An interesting correspondence can be seen from this. So, the voltage and the potential difference in this case are one and the same physical entity.
Superposition of electric fields
So, we have considered the main characteristics of the electric field. But in order to better understand the topic, we suggest that we additionally consider a number of parameters that may be important. And we will start with a superposition of electric fields. Previously, we considered situations under which there was only one specific charge. But there are a huge number of them in the fields! Therefore, considering a situation close to reality, let's imagine that we have several charges. Then it turns out that forces that obey the rule of
addition of vectors will act on the test subject
. Also, the
principle of superposition suggests that a complex movement can be divided into two or more simple ones. It is impossible to develop a realistic model of motion without taking into account superposition. In other words, under the existing conditions, the particle under consideration is affected by various charges, each of which has its own electric field.
Using
It should be noted that now the possibilities of the electric field are not used to their full potential. Even, more correctly, we almost never use its potential. As a practical realization of the possibilities of the electric field, we can bring the Chizhevsky chandelier. Earlier, in the middle of the last century, mankind began to explore space. But the scientists faced many unresolved issues. One of them is air and its harmful components. The Soviet scientist Chizhevsky took up the solution to this problem, who was also interested in the energy characteristic of the electric field. And it should be noted that he did a really good development. This device was based on the technique of creating aeroionic air flows due to small discharges. But in the framework of the article, we are interested not so much in the device itself as the principle of its operation. The fact is that for the functioning of the Chizhevsky chandelier, not a stationary power source was used, but namely an electric field! For the concentration of energy, special capacitors were used. The energy performance of the electric field of the environment significantly affected the success of the device. That is, this device was developed specifically for spaceships that are literally crammed with electronics. It was fed from the results of other devices connected to constant power sources. It should be noted that the direction was not abandoned, and the possibility of taking energy from the electric field is being investigated now. True, it should be noted that significant success so far has not been achieved. It is also necessary to note the relatively small scale of the research, and the fact that most of them are performed by volunteer inventors.
What are the characteristics of electric fields?
Why study them? As mentioned earlier, the characteristics of an electric field are intensity, voltage and potential. In the life of an ordinary ordinary person, these parameters cannot boast of significant influence. But when questions arise that something large and complex should be done, then ignoring them is inadmissible luxury. The fact is that an excessive number of electronic fields (or their excessive strength) leads to the fact that interference occurs during the transmission of signals by equipment. 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 noises of technology, excessively strong electronic fields can adversely affect the functioning of the human body. It should be noted that a small ionization of the room is still considered a blessing, since it contributes to the deposition of dust on the surfaces of a human dwelling. But if you look at how many various equipment (refrigerators, televisions, boilers, telephones, electric power systems, etc.) are in our homes, we can conclude that, alas, this is not good for our health. It should be noted that the low characteristics of electric fields almost do not harm us, since humanity has long been accustomed to cosmic radiation. But it’s so hard to say about electronics. Of course, to refuse all this will not work, but the negative impact of electric fields on the human body can be successfully minimized. For this, by the way, it is enough to apply the principles of energy-efficient use of technology, which provide for minimizing the operating time of mechanisms.
Conclusion
We examined what physical quantity is a characteristic of the electric field, where what is used, what is the potential of developments and their application in everyday life. But still I want to add a few final words about the topic. It should be noted that a fairly large number of people were interested in them. One of the most visible traces in history was left by the famous Serbian inventor Nikolai Tesla. He was able to achieve considerable success in this regard regarding 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 a lot of undiscovered opportunities.