An electric current is a flow of electric charge In electric circuits this charge is often carried by . Direct current is produced by sources such as batteries, thermocouples, This relationship is known as Joule's First Law. In metallic solids, electric charge flows by means of electrons, from lower to higher electrical potential. If the two requirements of an electric circuit are met, then charge will flow through the external circuit. The current is simply the ratio of the quantity of charge and time. from the positive terminal and toward the negative terminal of the battery. drift speed of an electron moving through a wire is the distance to time ratio. Discusses the difference between Conventional Current and Electron Flow.
The electrons possess energy - they spin. It is kind of a crazy jumping all around the place within the atom - it almost seems that they are each time in many places. Do they lose that energy over time? Are there different types of electrons - in respect to their content?
That's a challenging, diverse set of questions. Electrons, like all small things, are indeed fuzzed-out waves, not located in one exact place. The picture of them always hopping around, as if they were first somewhere then somewhere else, is not correct for electrons that have settled in to wave patterns in atoms.
However, and this should admittedly sound strange before you learn a little quantum mechanics even in those stable patterns the electrons have some kinetic energy. More importantly, whether classical or quantum, energy is conserved. The large-scale organized forms of it gradually trickle away into smaller-scale forms, allowing a great diversity of possible states.
Electron flow vs. current flow
That's the implication of second law of thermodynamics. Anyway, all this energy has been around since the Big Bang, as you supposed. The electron spin is something else, a part of what makes something an electron, and it persists undiminished unless the electron is annihilated. No, electrons are really all the same sort of thing. That's not just a philosophical statement. If you pick some spatial wave pattern, it can only have two electrons in it- one for each distinct spin state.
That has enormous consequences. For example, it's the only reason that all the electrons in an atom don't pile up in a boring low-energy ball near the nucleus, so it accounts for all of chemistry and hence life.
Electron flow vs. current flow
Hi there, I was wondering, is there an electron flow inside the actual cell itself once it is connected to a charger to charge the battery?? Thanks - Sohail age 23 Australia A: There's essentially no flow of individual free electrons inside the battery. However, there is a net flow of electrons since the ions include electrons. Since those ions still have electrons in them, there is electron flow. Yet because of collisions with atoms in the solid network of the metal conductor, there are two steps backwards for every three steps forward.
With an electric potential established across the two ends of the circuit, the electron continues to migrate forward. Progress is always made towards the positive terminal. Yet the overall effect of the countless collisions and the high between-collision speeds is that the overall drift speed of an electron in a circuit is abnormally low.
A typical drift speed might be 1 meter per hour. One might then ask: How can there by a current on the order of 1 or 2 ampere in a circuit if the drift speed is only about 1 meter per hour? Current is the rate at which charge crosses a point on a circuit. A high current is the result of several coulombs of charge crossing over a cross section of a wire on a circuit. If the charge carriers are densely packed into the wire, then there does not have to be a high speed to have a high current.
That is, the charge carriers do not have to travel a long distance in a second, there just has to be a lot of them passing through the cross section. Current does not have to do with how far charges move in a second but rather with how many charges pass through a cross section of wire on a circuit. To illustrate how densely packed the charge carriers are, we will consider a typical wire found in household lighting circuits - a gauge copper wire.
Each copper atom has 29 electrons; it would be unlikely that even the 11 valence electrons would be in motion as charge carriers at once. If we assume that each copper atom contributes just a single electron, then there would be as much as 56 coulombs of charge within a thin 0.
With that much mobile charge within such a small space, a small drift speed could lead to a very large current. To further illustrate this distinction between drift speed and current, consider this racing analogy. Suppose that there was a very large turtle race with millions and millions of turtles on a very wide race track.
Turtles do not move very fast - they have a very low drift speed. Suppose that the race was rather short - say 1 meter in length - and that a large percentage of the turtles reached the finish line at the same time - 30 minutes after the start of the race.
In such a case, the current would be very large - with millions of turtles passing a point in a short amount of time. In this analogy, speed has to do with how far the turtles move in a certain amount of time; and current has to do with how many turtles cross the finish line in a certain amount of time.
The Nature of Charge Flow Once it has been established that the average drift speed of an electron is very, very slow, the question soon arises: Why does the light in a room or in a flashlight light immediately after the switched is turned on? Wouldn't there be a noticeable time delay before a charge carrier moves from the switch to the light bulb filament?
The answer is NO! As mentioned abovecharge carriers in the wires of electric circuits are electrons. These electrons are simply supplied by the atoms of copper or whatever material the wire is made of within the metal wire. Once the switch is turned to on, the circuit is closed and there is an electric potential difference is established across the two ends of the external circuit.
The electric field signal travels at nearly the speed of light to all mobile electrons within the circuit, ordering them to begin marching.
As the signal is received, the electrons begin moving along a zigzag path in their usual direction. Thus, the flipping of the switch causes an immediate response throughout every part of the circuit, setting charge carriers everywhere in motion in the same net direction. While the actual motion of charge carriers occurs with a slow speed, the signal that informs them to start moving travels at a fraction of the speed of light.