Tell about Electric Currents ?

without any internal modifications. .

An induction generator usually draws its excitation power from an electrical grid.

Because of this, induction generators cannot usually "black start" a de-energized distribution system.

In other conductive materials, the electric current is due to the flow of both positively and negatively charged particles at the same time

In still others, the current is entirely due to positive charge flow. For example, the electric currents in electrolytes are flows of positively and negatively charged ions.

No, water would stay still. Still = no flow = no current without voltage.

In a common lead-acid electrochemical cell, electric currents are composed of positive hydrogen ions (protons) flowing in one direction, and negative sulfate ions flowing in the other.

For e.g. a battery there is voltage even it is not connected anywhere.

Electric currents in sparks or plasma are flows of electrons as well as positive and negative ions. In ice and in certain solid electrolytes, the electric current is entirely composed of flowing ions.

iin a metal, some of the outer electrons in each atom are not bound to the individual atom as they are in insulating materials, but are free to move within the metal lattice.

Current flow basically means the flow of electric charges

These conduction electrons can serve as charge carriers, carrying a current. Metals are particularly conductive because there are a large number of these free electrons, typically one per atom in the lattic

With no external electric field applied, these electrons move about randomly due to thermal energy but, on average, there is zero net current within the metal

At room temperature, the average speed of these random motions is 106 metres per second.[17] Given a surface through which a metal wire passes, electrons move in both directions across the surface at an equal rat

. As George Gamow wrote in his popular science book, One, Two, Three...Infinity (1947), "The metallic substances differ from all other materials by the fact that the outer shells of their atoms are bound rather loosely, and often let one of their electrons go free.

. Thus the interior of a metal is filled up with a large number of unattached electrons that travel aimlessly around like a crowd of displaced persons.

When a metal wire is subjected to electric force applied on its opposite ends, these free electrons rush in the direction of the force, thus forming what we call an electric current."

When a metal wire is connected across the two terminals of a DC voltage source such as a battery, the source places an electric field across the conductor.

The moment contact is made, the free electrons of the conductor are forced to drift toward the positive terminal under the influence of this field.

respect to time

The free electrons are therefore the charge carrier in a typical solid conductor.

electric circuit,

For a steady flow of charge through a surface, the current I (in amperes) can be calculated with the following equation:

when the electric charge is flowing in one direction

where Q is the electric charge transferred through the surface over a time t. If Q and t are measured in coulombs and seconds respectively, I is in amperes.