# Electric current and current flow

So electric current is due to negatively charged electrons. The voltage pushes valence electrons out of orbit from one atom into the next atom. Electricity can flow in an electric circuit by a battery.

One of the basic instruments to measure the current is pmmc instrument or permanent magnet moving coil instrument. That is how a light bulb …in a circuit lights up.

The rate at which charge enters the external circuit on one end is the same as the rate at which charge exits the external circuit on the other end. To treat the overall effect of the current, its direction is usually taken to be that of the positive charge carrier.

Let us consider the current due to flow of positive charges as conventional current flow. With that much mobile charge within such a small space, a small drift speed could lead to a very large current.

Electric current and current flow certain electrolyte mixtures, brightly coloured ions are the moving electric charges. To further illustrate this distinction between drift speed and current, consider this racing analogy.

Knowing that the actual charge carriers in wires are negatively charged electrons may make this convention seem a bit odd and outdated. Theory of Electricity Current in Metallic Conductor The main cause of current through a metallic substance is the flow of electrons that is the directional drift of free electrons.

The direction of an electric current is by convention the direction in which a positive charge would move. However, metal electrode surfaces can cause a region of the vacuum to become conductive by injecting free electrons or ions through either field electron emission or thermionic emission.

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. 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.

Nonetheless, it is the convention that is used worldwide and one that a student of physics can easily become accustomed to. The loss of energy is i2Rt joules. Current density Current density is a measure of the density of an electric current. Note that the speed of the individual electrons is quite …a bit less, and the average speed of the electrons is less than a millimeter per second.

A high current is the result of several coulombs of charge crossing over a cross section of a wire on a circuit. Current is the rate at which charge crosses a point on a circuit.

Current - the rate of charge flow - is everywhere the same. There is no place in the electrical circuit where charge carriers become consumed or used up. Thermionic emission occurs when the thermal energy exceeds the metal's work functionwhile field electron emission occurs when the electric field at the surface of the metal is high enough to cause tunnelingwhich results in the ejection of free electrons from the metal into the vacuum.

In fact, the charge carriers in semiconductors, street lamps and fluorescent lamps are simultaneously both positive and negative charges traveling in opposite directions. The answer is NO. 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 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 path of a typical electron through a wire could be described as a rather chaotic, zigzag path characterized by collisions with fixed atoms.

The electrons are moving together much like the water in the pipes of a home move. The picture of charge flow being developed here is a picture in which charge carriers are like soldiers marching along together, everywhere at the same rate.

Electric current is the rate at which electric charge flows past a point on the electric circuit. Water current is the rate at which water flows past a point on the water circuit. As such, current is analogous to the number of gallons of water flowing into, along, and out of a slide per unit of time.

Electric current flows from a high elecric potential to a low electric potential in a circuit. It is also opposite to the direction of the flow of electrons. Therefore, one-ampere current is equal to X 10 ^ 18 electrons should flow in one second.

Electric current is widely used in household and industrial appliances. Two types of electrical current are, one is alternating current is called an AC current and direct current is called us DC current. Ohm's law states that the electrical current (I) flowing in an circuit is proportional to the voltage (V) and inversely proportional to the resistance (R).Therefore, if the voltage is increased, the current will increase provided the resistance of the circuit does not change.

Electric current is the rate at which electric charge flows past a point on the electric circuit. Water current is the rate at which water flows past a point on the water circuit. As such, current is analogous to the number of gallons of water flowing into, along, and out of a slide per unit of time.

Sep 20,  · its lightning, for a more simple answer. electric current flow is the movement of charges. Most often, however, we consider electric current flow to be moving electrons, or electron current flow.

Electric current and current flow
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Which way does electric current flow