Magnetic Effects of Current

Whenever an electric current flows through a current-carrying wire or coil, a magnetic field is generated around it. This idea underpins the operation of various gadgets, such as the electric bell. In contrast to this, if a constant shift in the magnetic field is achieved, it is possible to generate an electric current. This is how the terms electricity and magnetism have come to be used interchangeably today. Transmittance of electric current occurs from distant energy generation stations to houses via high tension wires, transformers and distribution networks.

What are the Magnetic Effects of Current?

The creation of a magnetic field around an electric current in a wire is achieved by the use of a wire. H.C. Oersted, a Danish scientist who worked in the field of optics, was the first to detect this phenomenon in 1820. Consider the use of a conducting wire ( like copper) to demonstrate this:

• Assemble the battery by connecting the two ends with the help of connecting wires. Maintain a magnetic needle in a straight line parallel to the conducting copper wire. 

• During the completion of the circuit, the magnetic needle exhibits deflection. 

• A magnetic field is generated around a conductor when an electric current travels through it.

• When the current is increased, the amount of deflection increases proportionally. 

• When the direction of electric current flow is reversed (for example, by reversing the end of the battery), the direction of deflection in the magnetic needle is reversed as well. 

• As soon as the current flow is interrupted, the deflection of the magnetic needle is likewise interrupted. 

• As a result of the flow of electric current via a conducting wire, a magnetic field is created. 

Magnetic Effects of Current 

Magnetic effects of current can be understood through various principles and applications which are indicated below.

Magnetic field due to current through a straight conductor:

• The magnetic field created by a current-carrying straight wire is proportional to the distance between it and the source of current and it is proportional to the current travelling through it. 

• As a result, we can conclude that the current-carrying conductor generates a magnetic field surrounding it. 

• The Right-Hand Thumb Rule can be used to determine the direction of this magnetic field.

The Right-Hand Thumb Rule

• Following the Right-Hand Thumb Rule, if the thumb of the right hand points in the direction of the current, the remaining curled fingers of the same hand point in the direction of the magnetic field caused by the current.

Magnetic field due to current through the circular loop

• While the magnetic field produced by the current flowing through a circular loop is uniform in the centre of the current loop, it is non-uniform near the circumference of the loop.

• The magnetic field produced will have the same magnitude and direction in both directions. As a result, the field increases in size with each turn. There will be an equal number of current-carrying loops as there are turns and the field will be repeated n times.

Magnetic field due to current in a solenoid

• When a solenoid is activated, the magnetic field it produces is similar to that of a bar magnet. The strength of the magnetic field is related to the number of turns in the coil and the amount of current flowing through it. 

• Magnetic materials can be magnetised by generating a strong magnetic field within the solenoid’s inner workings.

Electromagnetic induction

In the 18th century, Michael Faraday found that if adjustments are made to the magnetic field, electric current can be generated in the manner given below: 

• It is possible to change the number of magnetic lines of force associated with a coil of a good conducting wire when it is rotated between the poles of a magnet. 

• If a magnet moves within the coil, the current changes in the same way. 

• Upon this occurrence, current begins to flow through the coil. 

As a result, electromagnetic induction is defined as the generation of an electric current across a conductor that is travelling through a magnetic field.

Electric generator

It is also possible to generate large amounts of current for use in homes and industry by using the principle of induced current generation, which is based on the phenomenon of electromagnetic induction. 

• In an electric generator, mechanical energy is used to rotate a conductor in a magnetic field, resulting in the generation of electrical current.

• It is necessary to use a split-ring type commutator in order to obtain direct current (DC), which does not change its direction with time. With this configuration, one brush is always in contact with the arm that is moving up in the field, while the other brush is always in contact with the arm that is moving down in the field. The operation of a split ring commutator in the context of an electric motor has been demonstrated. As a result, a unidirectional current is generated.Hence, the generator is referred to as a direct current generator.

Conclusion 

While in the presence of a magnetic field, the conductor carrying current feels a force acting on it. When a conductor is parallel to a magnetic field, the experienced force will be directed in a direction that is perpendicular to the conductor and the magnetic field. When the conductor is parallel to the magnetic field, it is not subjected to any magnetic field. The strength of the magnetic field is proportional to the current flowing through the conductor and vice versa. The strength of the magnetic field increases proportionally to the increase in current. When the current flowing through the conductor decreases, the strength of the magnetic field diminishes as a result of this decrease.