Electric and Magnetic Field

Energy can never be created. It can only be transformed from one form to another. There are various types of energies that give rise to various types of energy fields.

The electric field and the magnetic field are such invisible fields of energy. They are often related to each other.

The electric field is formed around an electrically charged particle. Similarly, the magnetic field is formed around a magnetic object. However, magnetic fields can also be created within electric conductors and wires. Both electric and magnetic fields are invisible and they can only be experienced.

Electric field

Before we study the association of electric and magnetic fields, let us study them individually.

The electric field is the field of energy or charge which surrounds a positively or negatively charged electric particle.

When a test positive or negative charge enters the electric field of the source charge, it experiences a push or pulls force.

If the charges on test and source particles are opposite, then a force of attraction exists between them.

However, if the charges on test and source particles are similar to each other, then these charges repel each other.

Electric field measurement and units:

The strength of an electric field is measured by how much electric charge is experienced by the unit test particle which enters the electric field of the source particle.

The formula to calculate the electric field is given below.

Electric field = Force/Charge is the intensity of electric field.

Michael Faraday, who first introduced the concept of an electric field, called it the line of force. The more the density of the lines of force, the stronger is the electric field.

The less the density of the lines of force, the less is the strength of the electric field.

Magnetic Field

When motion is exhibited by the electric charges, they interact with each other. Such interaction between electric charges that move and the magnetic materials is described by the magnetic field.

The direction of a magnetic field is perpendicular to the electric field. Magnets are of two types:

• The Permanent Magnets:

These magnets attract or repel the poles of ferromagnetic elements such as iron, cobalt and nickel.

• The Temporary Magnets:

The temporary magnets are usually electrostatic magnets formed due to the electric current and electric field.

A magnetic field surrounds both temporary and permanent magnets.

The magnetic field is a type of vector quantity that has direction and magnitude. 

The symbol used to represent the magnetic field is ‘H.’ 

Unit and Measurement of Magnetic Field

The magnetic field describes the area in which the magnetic force can be experienced. The strength of this magnetic field is measured with the help of the magnetic flux. The S.I unit of this Magnetic flux is kilogram per second square per ampere. The common unit used for magnetic flux is Tesla. Tesla is a magnetic field unit.

The value of one Tesla is equal to one weber per square metre. 

The magnetic fields have large applications in today’s technology. 

Earth, our planet, has its own magnetic field, which envelopes the earth. These magnetic fields protect the Ozone layer from solar winds. The compass works because of this magnetic field.

The Correlation between the Electric Field and the Magnetic Field

The electric field and the magnetic fields are two phenomena closely related to each other.

An electric field will lead to the formation of a magnetic field,and a magnetic field leads to the formation of an electric field.

Such a field consisting of the electric field and the magnetic field is called an electromagnetic field.

Following are the features of the association of the electric and magnetic fields:

• The cause of both electric and magnetic fields is the moving charges.
• The electric field and the magnetic field both interact with each other.
• The electric field and magnetic field both exert forces on electric charges.

The forces that act on a particle that enters an electromagnetic field are given below:

• Lorentz Force: This force is exerted due to the following electromagnetic field.

• Electric Force: This force is produced due to the electric field and has directed the same as the electric field.

• Magnetic Force: This force is generated by the magnetic field, and direction is perpendicular to the magnetic field and the moment of the charge, that is, the current.

A magnetic field that keeps varying constantly leads to the formation of the electric field.

An electric field that undergoes constant variation leads to the formation of a magnetic field. 

This is how the electric fields in the magnetic field are related to each other.

Long exposure to electromagnetic fields and radiation can harm human health.

Conclusion

The interaction of the positive and negative charges leads to the formation of two types of fields: The electric field and the magnetic field. The electric field is formed around electrically charged particles. When these electrically charged particles move in an electric current, it leads to the formation of the magnetic field. The magnetic field is also formed around magnetic materials.

The electric field and the magnetic field interact with each other to form an electromagnetic field. The electromagnetic field has wide applications such as kitchen appliances, MRI scanning, the compass, which helps tell us direction, etc.