Magnetic Field Lines, Formula & Definition

Endless lines of force (or magnetic flux) that originate from the north-seeking poles of a magnet and join south-seeking poles can be used to illustrate magnetic fields. The density of the lines indicates the size of the field, with more density at the poles (where the field is strong) and less density as they move away from the poles.

What is a magnetic field?

Magnets are used in a variety of ways and have umpteen applications. Small fridge magnets, speakers, computer devices, and even medical equipment like magnetic resonance imaging (MRI) scanners contain them. All magnets, regardless of size, have two poles: north and south magnetic poles. Magnetic poles with similar magnetic poles attract one another, while poles with opposite magnetic poles repel each other. Any magnet produces a magnetic field that attracts other magnetic materials. 

What is a Magnetic Field?

A magnetic field is an area around a magnet where the magnet’s magnetism is active. Any magnet generates its magnetic field, can communicate with other magnets, and even attract magnetic materials. The iron nail gets drawn toward a bar magnet even though they are not in direct touch. Only at a certain distance from the magnet does a magnetic field exist. As the distance between the magnet reduces, its strength grows, and as the distance increases, it diminishes.

Definition of magnetic field

Magnetic fields can be classified in various ways depending on the situation. An unseen field attracts magnetically sensitive items with its magnetic pull. Magnets produce magnetic fields that exert forces and torques on one another.

They can be produced by an electric current or a changing electrical field. They are dipolar, which means they have two magnetic poles, one north, and one south. The Tesla is the SI unit for measuring magnetic fields, while Gauss is the SI unit for measuring lesser magnetic fields (1 Tesla = 10,000 Gauss). 

A magnetic field is a region where a magnetic material or moving charge experience magnetic force. According to the Lorentz Force Law, the magnetic force is measured, F = qvB, where F is a magnetic force, q is the charge, v is the velocity, and B is a magnetic field.

This is a vector product, where F is perpendicular to all other values (->).

The formula of magnetic field

The 𝑐𝑜𝑛𝑠𝑡𝑎𝑛𝑡 𝜇₀ is included in the magnetic field formula. This is known as free space permeation, and it has a 𝑣𝑎𝑙𝑢𝑒 𝜇₀  4π=  410^-7 (Tm/ A). Furthermore, Tesla is the unit of magnetic field (T).

Magnetic field= (𝑝𝑒𝑟𝑚𝑒𝑎𝑏𝑖𝑙𝑖𝑡𝑦 𝑜𝑓 𝑓𝑟𝑒𝑒𝑠𝑝𝑎𝑐𝑒) (𝑐𝑢𝑟𝑟𝑒𝑛𝑡 𝑚𝑎𝑔𝑛𝑖𝑡𝑢𝑑𝑒)/2𝜋(𝑑𝑖𝑠𝑡𝑎𝑛𝑐𝑒)

                  B = 𝜇₀I/2𝜋𝑟

Vector field

The magnetic field is mathematically described as a vector field. The magnetic field is thought to have both magnitude and direction. A collection of vectors drawn on a pattern can be used to represent the vector field. Each vector’s direction corresponds to the compass’s orientation. The magnetic force’s power determines the length of the vector.

What are magnetic field lines?

Magnetic field lines are fictitious lines that run around a magnet. The density of a field’s line indicates its magnitude. The magnetic field is stronger towards the South and North Poles of a magnet and weakens as it goes away from the poles. 

Properties of magnetic field lines

• Magnetic field lines never cross one another. 
• They travel the shortest distance between the magnetic poles with the least resistance—a bar magnet’s magnetic lines of force form complete loops from one pole to another.
• Magnetic field lines will have the same length.
• The magnetic field density is proportional to the distance from a pole. The density reduces as the distance from a pole increases.

Detecting magnetic fields with a compass

It is also worth noting that the earth’s magnetic poles experience periodic reversals and fluctuations over time. Furthermore, the magnetic poles do not align perfectly with the geographic north-south axis. Magnetic declination is the difference between the two, so not all compasses include the settings. 

When a compass is put close to the magnetic field, the needle runs parallel to the field’s direction. The needles at the north pole of the magnet point right out and out from the magnet, whereas the needle at the south pole points right into the magnet.

Conclusion 

This article explains the magnetic field lines. Magnetic field lines are fictitious lines that run around a magnet. The magnetic field lines are stronger towards the South and North Poles of a magnet and weaken as it goes away from the poles. Magnetic field lines are used throughout modern technology, notably in electrical engineering and electromechanics; professionals must understand them.