Actuality of the electric current

The terminology used in this article: [] indicates subscript. ~A means the vector A. means 4.

9 Electric current similar to water current Ed 01.12.31 ----------------------------------------- Abstract

-------- A perfect comparison between a closed circuit of water current and a closed circuit of electric current is made and Ohm's law is obtained in this manner and it is shown that, contrary to the current belief, existence of conduction current is not because of the existence of any electric field in the conductor, and the linear relation ~J=g~E cannot be valid. The relaxation time (necessary for the current to reach its final speed) and the final speed (drift velocity) of the current are obtained in the above-mentioned manner, and it is shown that, contrary to what is believed at present, both of them are independent of the chosen standard unit charge (eg electron charge or coulomb) and its mass. It is also shown that, contrary to the current belief, alternating current is steady. We also prove the existence of a kind of resistance arising from the configuration of the circuit. Action mechanism of transistor is explained and a hydrodynamical analogue for it is introduced: both confirming the material presented earlier.

I. Introduction

--------------- What is presently propounded as the existence cause of an elrectric conduction current in a conductor is the existence of some electric field arising from the power supply (sourcs) in the conductor and the response of the conductor to this field in the form of producing current density (eg in the form of ~J=g~E for an ohmic material). In other words it is thought that existence of the conduction current necessitates existence of an electrostatic field porducing it, and also existence of the potential difference necessitates existence of an electrostatic field causing it.

And then an entire similarity is considered between the electrostatics and the subject of electric current, eg as in the electrostatics, the curl of the above mentioned field is considered equal to zero in the conductor and then eg it is tried that a conduction problem to be solved in the same way as an electrostatic problem (by obtaining appropriate solution to Laplace's equation (see Foundations of Electromagnetic Theory by Reitz, Milford and Christy, Addison-Wesley, 1979)).

In this article considering the entire similarity existent between the electric current and mechanical current of water it is shown that, really, existence of the conduction current does not necessitate existence of any electrostatic field in the conductor (or wire) carrying the current, and the potential difference here is other than the potential difference in the electrostatics, and in this manner we obtain Ohm's law.

II. Water circuit and Ohm's law

------------------------------- Consider the water circuit shown in Fig. 1.

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(b)

Fig. 6. The current-carrying looped wire makes the electron move in the loop.

It is obvious that the current in the part ab of each of the "going" and "backing" paths is still from left to right having the same amount of the circuit current.

Now let's make these two parts (ab's) in (gentle) contact with each other. What is the situation of the current in this double part of ab now? If the (above-mentioned) resistance arising from the configuration of the wire did not exist, the most correct answer would be that we should not expect any alteration and as the path of the current would have become double in the distance between a and b (being both the "going" and "backing" paths) the current would be two times more than the general current of the circuit (becasuse of the general current of the circuit both in the "going" and "backing" paths of ab). But certainly this is not the case completely, and due to the contact of the two "going" and "backing" parts of ab a part of the previously mentioned stresses will be redistributed (trying to become minimum) and then the above-mentioned resistance, arising from the configuration, will change and then the current in the loop and also in

the common part of ab will be other than the case before the contact; the quite clear reason for this statement is that when the two parts of ab are in contact we expect in principle that because of the positioning of a before b the current in the loop to be counterclockwise (from a to b) not clockwise (from b to a) as before the contact.

Now imagine that these parts of ab are welded together, and in the distance between a and b we have only a single wire with a thickness equal to the wire thickness in other parts of the circuit (and loop). In this state if we want to visualise the situation just before the contact of the two "going" and "backing" parts of ab as one we explained above, we must say that before the above-mentioned gentle contact the cross-section of the circuit in the "going" part of ab and also in the "backing" part of ab is half of the cross-section in other parts of the circuit, then the speed of the electrons in each of the two "going" and "backing" parts of ab is twice as more as the electrons speed in other parts of the circuit. Now, if these two slenderized "going" and "backing" parts of ab are to be brought into contact with each other (welded together) and also if the currents are not to be changed, the situation will be as shown in Fig. 7, ie as we see in this figure, according to the above reasoning assuming ineffectiveness of the configuration on how the current is distributed, we expect that the current in the part ab of the circuit to be twice as more as the general current of the circuit halh of which, of course, will be canceled as the "backing" (counterclockwise) current in the loop.

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Fig. 7. What is the situation of current in the part ab and in the loop?

It is obvious of course that this won't be the case in practice, because, as a rule, as we said, we expect in principle that because of the positioning of the point a before b in the current path the current in the loop to be (clockwise) from a to b.

The conclusion we can decisively draw is that, anyway, the inclination existent in the circuit to produce a counterclockwise current in the loop before the contact of the two previously separated parts of ab, now after the contact (or welding of the two parts), depending on the configuration of the current-carrying wire of the loop relative to the configuration of the main wire of the circuit, will have a noticeable effect on the current which as a rule is expected to be clockwise in the loop (because of the point a being before b); and, in practice, the current in the loop may be even counterclockwise, even with little current, depending on the case; ie in other words we can have a negative resistance (of the configuration kind) causing the current in the part between a and b to be more than the general current of the circuit. We have pointed to such a case in the 8th article of this book. We can also try the experiment suggested in Fig. 8 in order to see whether the current in the loop is clockwise or counterclockwise, and with what current.

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Fig. 8. Is the current in the loop clockwise or counterclockwise?

V. Action mechanism of transistor

--------------------------------- As a general confirmation of the mechanism presented in this article for the resistance arising from the configuration of the current path and also of the validity of the comparison made between the electric current and water current we shall proceed to describe the action mechanism of transistor in this section.

We know that some different materials gather electrostatic charge when robbed with each other. Consider two typical materials of this kind and call them 1 and 2. Assume that some electrons will flow from 1 to 2 when they are brought into contact. Important for us in this discussion is the tendency (due to any reason, eg the molecular structure of the materials) existent in the contact between 1 and 2 to cause the electrons to flow from 1 to 2.

Now let's connect the negative pole of a battery to 1 and its positive pole to 2. The battery tends to make the electrons flow from its negative pole to its positive pole in a circuit external to the battery a part of which is the battery itself. Such a flow will be from 1 to 2 considering the above-mentioned connecting manner. But as we said, regardless of the stimulation of the battery, the materials 1 and 2 themselves have a tendency to establish an electron current from 1 to 2. Thus, it is obvious that the battery will establish a current of electrons, from 1 to 2, in the circuit without encountering much resistance (due to the junction

1-2).

But when the negative pole of the battery is connected to 2 and its positive pole is connected to 1, the battery as before wants to produce a current of electrons from its negative pole to its positive pole in the circuit a part of which is the battery itself, and this necessitates flow of electrons from 2 to 1 which is opposite to the natural tendency of the junction

1-2; thus, the electron current of the circuit will encounter much resistance at the junction 1-2. In other words for prevailing over this additional

resistance in order to have a current with the same intensity as before in the circuit it is necessary to use a battery with a higher voltage.

Let's show the tendency of a junction to establish a current of electrons by an arrow in the direction of this tendency. Suppose that we have two adjacent junctions of the above-mentioned type (having natural tendency to make the electrons flow) but with two opposite directions of tendency in a single block; see Fig. 9. We name such a block as transistor.

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