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# What Is A Magnetic Field? Definition, Symbol And Characteristics

A space in which magnetic phenomena take place due to the influence of a body with magnetic properties, be it a magnet or a magnetized ferromagnetic material, is called a magnetic field.

## What Is A Magnetic Field?

The magnetic field in physics is also defined as a vector magnitude that accounts for magnetic intensity, that is, it expresses the phenomenon of attraction between a magnet and certain materials ( cobalt and iron ). These magnets can be made of different types of materials, and always have a north pole and a south pole.

The magnetic field is not about the force itself but about a space in which that force is exerted as a result of the movement of electric charges. In it, forces act on charged particles in motion, which gives it its vector character.

### Symbol And Unit Of Magnetic Field:

Symbol: B or H

Unit: Tesla

Base Unit: (Newton.Second)/Coulomb

## How A Magnetic Field Is Represented?

The magnetic field is represented by the drawing of imaginary lines, which are called lines of magnetic force or magnetic field lines.

## Characteristics Of Magnetic Field:

• It has a north pole and a south pole.
• Opposite poles attract and like poles repel.
• It can be generated from moving electric currents or magnets.
• The closer a magnetic field is to the point of origin, the greater its intensity.
• Its propagation occurs at the speed of light.
• It is represented by the so-called magnetic field lines.

## What Are Magnetic field lines?

The presence of a magnet alters the space that surrounds it and forces the iron filings to be arranged following a specific pattern, that is, it forces them to align.

This alignment is not random but occurs in the direction of the magnetic field, which gives rise to the recording of a magnetic spectrum .

The ends where such lines meet are called magnetic poles . The external lines of the magnet are recorded from the north pole to the south pole, while the internal lines are recorded from the south pole to the north pole. This results in closed lines. Magnetic field lines never cross each other.

Vector B has the same direction as the field line of each point and is tangent to it. Its intensity will be greater at the point where the lines concentrate.

## Magnetic field units

In the International System, the unit of magnetic field is called Tesla and is abbreviated with the sign T. One Tesla is equal to one weber per square meter.

The magnetic field, as a vector quantity , is represented with the following sign:

The intensity of the magnetic field is represented by the sign H and is expressed or measured in amperes per meter .

The strength of the magnetic field is represented by the letter F , whose unit of measurement is the newton ( N ).

For its part, the mass of the magnetic pole is represented by the letter m .

## What is Magnetic field intensity?

The force that is exerted in the field on the unit of the North Pole, applied at a point, is called magnetic field intensity. To calculate the intensity of the magnetic field, the following formula is applied : H = F/m.