We all know that electricity is a stream of charged particles directed by the impact of the electric field.This will tell you any student.But the question of what is the direction of the current, and what happens to these same particles, many can stump.
real question
As you know, in a conductor electricity electron transfer in electrolytes - cations and anions (or simply ions), electrons in semiconductors work with so-called "holes" in the gases - ions and electrons.From the availability of elementary particles in a given material, and depends on its conductivity.In the absence of an electric field in the metal current conductor will not go.But once its two sections a potential difference, i.e.will be tension in the movement of electrons and stop the chaos comes order they will start from the minus and headed towards plus.It would seem that the answer to the question "What is the current direction?".But there it was.It is enough to look into the encyclopedia or just in any physics textbook, like immediately becomes much a contradiction.It says that the conditional phrase "current direction" refers to the directional movement of positive charges, in other words, from plus to minus.What to do with this statement?It is noticeable to the naked eye contradiction!
force of habit
When people learned to make the DC circuit, they did not know of the existence of the electron.Moreover, at the time I did not know that he is moving from minus to plus.When the amp offered in the first half of the 19th century, the current direction from plus to minus, all took it for granted and the decision no one disputed.It took 70 years, until people found out that the current in metals is due to the movement of electrons.And when they realize (it happened in 1916), all so used to the choice made by Ampere that already did not change anything.
«Golden Mean»
electrolytes negatively charged particles move toward the cathode, and the positive - to the anode.The same thing happens in the gases.If you think about what direction the current is in this case, comes to mind only one option: move bipolar electric charges in a closed circuit going towards each other.If we take this statement as a basis, it will remove the existing conflict today.It may be surprising, but more than 70 years ago, scientists have documented that the opposite sign electric charges in a conducting medium is really moving toward each other.This statement is true for any conductor, regardless of the type of metal, gas, electrolyte, semiconductor.Whatever it was, it is hoped that over time physics eliminate confusion in terminology and take an unambiguous definition of what is it that is the direction of the current.Habits, of course, change is difficult, but you need to at last put everything in its place.
