Electric Current and its Effects

Electric current is defined as the rate at which charged particles such as electrons or ions move in a conductor or electric circuit. It is measured in Coulombs/second, which is known as Ampere. The SI unit of electric current is Ampere(A).

Electric current is defined as the amount of charged particles passed through an electrical wire or conductor per unit of time. Electric current is a scalar quantity, and an ammeter measures it. An ammeter is a device used to measure the current flowing in an electric circuit. 

What are Electrons?

Electrons are minute-charged particles and exist within the molecular structure of any substance. Molecules are made of multiple atoms, made up of charged particles like electrons, protons, and neutrons. 

Electrons revolve around the nucleus in various circular orbits depending on the number of electrons an atom has, and every circular orbit consists of 8 electrons. The electrons revolving in 1st or 2nd orbits are tightly held because of the strong electrostatic force between them. In contrast, electrons revolving in the last orbit are loosely held, hence called free electrons. These free electrons can flow freely through the conductor. This flow of free electrons across the conductor constitutes an electric current.

Electrons are bonded to the nucleus by a strong electrostatic force that keeps the electrons in orbit. With a small amount of energy, electrons can break this electrostatic force and move out of the orbit of an atom and flow freely in the matter, and the force required to drive the current flow is termed voltage.

The principle that defines the electric current

In most DC electrical circuits, resistance to the electric current is constant; hence electric current is related by voltage and resistance. Ohm’s Law defines this relation.

Ohm’s Law: It states that electric current flowing through a conductor is directly proportional to the voltage applied to the conductor

I        =    V / R

R is the constant of proportionality, and it is termed resistance.

Resistance is defined as the ratio of voltage to electric current.

SI Unit of an Electric current

The magnitude of electric current is measured in coulombs per second. The SI unit of electric current is Ampere and is denoted by the letter A.

               1C

1A =        —

                1s

1 Ampere is defined as one coulomb of electric charge moving past a specific point in one second.  If 6.241 x 1018  electrons flow through the conductor in one second, the electric current flowing through the conductor is called One Ampere (A). 

Effects of an Electric Current

Heating effect of an electric current. When an electric current flows through the conductor, heat is generated and warms the conductor. The motion of electrons in the conductor converts the electrical energy, i.e., current, into heat energy.

This equation defines the heat generated in a conductor: H=I2RT

The heating effect depends on the below factors:

• Time: The longer the current flows in a conductor, the greater the heat generated.

• Resistance: The higher the resistance across the conductor, the more heat generated in the conductor.

• Current: The larger the amount of current, the higher the heat generated.

Magnetic Effect of Electric Current: A magnetic field is generated when the electric current flows through a conductor. This effect can be observed when a compass needle is placed near the current-carrying wire, the needle deflects, detecting the presence of the magnetic field, and the Right-Hand Thumb rule determines the direction of the field generated.

The Right-Hand Thumb Rule: If you are holding a current-carrying conductor in your right hand, such that your thumb points in the direction of the electric current, then the fingers wrapped around it show the direction of the magnetic field generated by the electric current.

Chemical Effect of Electric Current: When an electric current is passed through a chemical solution, the solution breaks down into ions. Metal Ions are positively charged. After all, they donate electrons, and nonmetals are negatively charged because they have excess electrons.

The ionisation of the solution happens because of a chemical reaction that takes place when an electric current passes through the solution.

Depending on the nature of the solution and types of electrodes used, the below effects are observed:

• Change in colour of the solution.

• Metallic deposits on electrodes.

• Production of bubbles or release of gas in a solution.

Conclusion

Electricity is the most basic phenomenon associated with the electric current. Electric current and its effects range widely to various different phenomena in science. Electricity giving rise to magnetic fields is also another great discovery related to electric current. Current law, voltage law, Ohm’s law, and Coulomb’s law are some of the principles related to electric current. The right-hand thumb rule states electricity gives rise to magnetic fields. The same is also possible vice-versa. The magnetic field can also generate electric current, and Fleming’s Right-hand Rule supports this.