what is current? how it flows in conductor?

Answer 1

(m)

Current is a flow of electrical charge carriers, usually electrons or electron-deficient atoms. The common symbol for current is the uppercase letter I. The standard unit is the ampere, symbolized by A. One ampere of current represents one coulomb of electrical charge (6.24 x 1018 charge carriers) moving past a specific point in one second. Physicists consider current to flow from relatively positive points to relatively negative points; this is called conventional current or Franklin current. Electrons, the most common charge carriers, are negatively charged. They flow from relatively negative points to relatively positive points.

Electric current can be either direct or alternating. Direct current (DC) flows in the same direction at all points in time, although the instantaneous magnitude of the current might vary. In an alternating current (AC), the flow of charge carriers reverses direction periodically. The number of complete AC cycles per second is the frequency, which is measured in hertz. An example of pure DC is the current produced by an electrochemical cell. The output of a power-supply rectifier, prior to filtering, is an example of pulsating DC. The output of common utility outlets is AC.

Current per unit cross-sectional area is known as current density. It is expressed in amperes per square meter, amperes per square centimeter, or amperes per square millimeter. Current density can also be expressed in amperes per circular mil. In general, the greater the current in a conductor, the higher the current density. However, in some situations, current density varies in different parts of an electrical conductor. A classic example is the so-called skin effect, in which current density is high near the outer surface of a conductor, and low near the center. This effect occurs with alternating currents at high frequencies. Another example is the current inside an active electronic component such as a field-effect transistor (FET).

An electric current always produces a magnetic field. The stronger the current, the more intense the magnetic field. A pulsating DC, or an AC, characteristically produces an electromagnetic field. This is the principle by which wireless signal propagation occurs.

Answer 2

Electrical current doesn't actually "flow" in a conductor. What happens is that as voltage is applied to the conductor its energy excites the first electron in the conductor. That electron in turn excites the next electron, and so on through the length of the conductor. So, electrons don't "flow," but energy is transferred along the conductor.

Answer 3

Hello Chandra.

1. Current : It can be CONVENTIONALLY defined as the flow of (+)ve charges from higher to the lower potential. But as we all do well know that (+) charges i.e. protons can't ever come out of the atom and flow...... so PHYSICALLY accepted charge carrirer is an electron. This implies that curent is the "Rate of flow of electrons from a lower to a higher potential".
2. Conductors, the metallic substances, have free electrons which are in random motion, always. When a pretty good amount of voltage or potential difference is applied across its ends, the electrons orient up and begin to flow in one direction, opposite to which is the direction of the CONVENTIONAL CURRENT.

Additional subjects to refer :
1. Resistance.
2. Conductance.
3. Resistivity
4. Capacitance.
5. Superconductivity
6. Semicunductivity.

Answer 4

Curent is the flow of electrons. If two ends of a conductor are at different potentials, the current flows from point higher potential to the point of lower potential.

Answer 5

Current is due to the flow of electrons......In a conductor there r a lot of free electrons(valance electrons) with no potential these electrons move in random directions,but due to an applied potential these electrons move or flow in a particular direction(i.e from +ev to -ev) hence v feel the presence of electricity....The rate of flow of current is given by
i=dq/dt
where,i is the current.
Omh's law gives an relation of current n potential,i.e how r they dependent.It states that when the potential is large,current also increases.
V=IR
where R is the resistance,
V is the potential.

Answer 6

current is flow of electrons. Conductors have free valence electrons that help in the flow of electrons or electriccity. As an electron enters a conductor an electron leave the conductor too.
Got it!!!

Answer 7

Electric current is the flow of electric charge. The SI unit of electric currents is the ampere (A), which is equal to a flow of one coulomb of charge per second
In solid conductive metal, with no external forces applied, there exists a random motion of "mobile" or "free" electrons created by the thermal energy which the electrons have gained from the surrounding medium. When a metal atom contributes a free electron, it acquires a net positive charge. The population of freed electrons form a "charge-gas" or "sea of charge" which remains bound to the ion lattice by attraction, while the metal as a whole remains neutral. Metal atoms typically contribute either one or two electrons to the "sea." Free electrons can move amongst these positive ions, while the positive ions can only oscillate about their mean fixed positions. Electrons move, but the net flow of charge remains zero: given an imaginary plane through which the wire passes, the number of electrons moving from one side to the other in any period of time is exactly equal to the number passing in the opposite direction.

Answer 8

A current is the flow of a fluid, common examples are water or air. A current is any continuous, directed movement of a fluid. Naturally occurring currents can be explained as an increase in entropy.

In a river or stream, the water is influenced by gravity, and flows downhill to reduce its potential energy. The movement of water in a stream is called the current and this movement will vary from place to place and time to time dependent upon the volume of water, the slope, and the shape. In tidal zones, the current in rivers and streams may reverse on the flood tide before resuming on the ebb tide.

Air currents may be caused by differences in temperature, pressure, or impurity concentration. Temperature differences can cause air currents because warmer air is less dense than cooler air, causing the warmer air to appear "lighter." Thus, if the warm air is under the cool air, air currents will form as they exchange places. Pressure differences also cause air currents as the air flows from areas of higher pressure to areas of lower pressure. Impurities cause air currents due to entropy, which is the natural tendency of a system to move to a disordered state. For example, if perfume is sprayed in the corner of a closed room, it will eventually disperse evenly to the entire room..

Answer 9

Current is the rate at which charge flow in an electrical circuit.The carriers of charge in the electrical circuit r known as the electrons.The direction of the flow of current is opposite to the flow of conventional current.the unit of current is ampere.it is measured using an ammeter.

Answer 10

Current is the flow af electrons. An electrical potential (voltage) cause the electrons to move.