Tell about Electric Currents ?

the current will flow in the opposite direction.

From Ohm's law, the current can be defined as the voltage through the circuit per unit resistance.

More generally, electric current can be represented as the rate at which charge flows through a given surface as:

Electric currents in electrolytes are flows of electrically charged particles (ions)

For example, if an electric field is placed across a solution of Na+ and Cl− (and conditions are right) the sodium ions move towards the negative electrode (cathode), while the chloride ions move towards the positive electrode (anode). Reactions take place at both electrode surfaces, neutralizing each ion.

An electric current is a flow of electric charge.An electric current is a flow of electric charge.

Water-ice and certain solid electrolytes called proton conductors contain positive hydrogen ions ("protons") that are mobile. In these materials, electric currents are composed of moving protons, as opposed to the moving electrons in metals.

In electric circuits this charge is often carried by moving electrons in a wire.

In certain electrolyte mixtures, brightly coloured ions are the moving electric charges. The slow progress of the colour makes the current visible.[18]

It can also be carried by ions in an electrolyte,

by both ions and electrons such

s in an ionised gas (plasma). ... Electric current is measured using a device called an ammete

In air and other ordinary gases below the breakdown field, the dominant source of electrical conduction is via relatively few mobile ions produced by radioactive gases, ultraviolet light, or cosmic rays. Since the electrical conductivity is low, gases are dielectrics or insulators.

heating effect,

chemical effect,

However, once the applied electric field approaches the breakdown value, free electrons become sufficiently accelerated by the electric field to create additional free electrons by colliding, and ionizing, neutral gas atoms or molecules in a process called avalanche breakdown.

magnetic effect.

Heating effect of current converts useful electrical energy into heat

The breakdown process forms a plasma that contains enough mobile electrons and positive ions to make it an electrical conductor. In the process, it forms a light emitting conductive path, such as a spark, arc or lightning.

This unavoidable heating will increase the temperature of the components used in electrical circuit and alter their properties.

Heating in the conducting wire heats the insulation of conductors and detoriorates the insulating cover of the conductor.

Plasma is the state of matter where some of the electrons in a gas are stripped or "ionized" from their molecules or atoms. A plasma can be formed by high temperature, or by application of a high electric or alternating magnetic field as noted above

Since a "perfect vacuum" contains no charged particles, it normally behaves as a perfect insulator

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.

the metal is high enough to cause tunneling, which results in the ejection of free electrons from the metal into the vacuum.