Magnetic Dipoles

The field generated by magnets is known as the magnetic field. Every magnet has its capacity for generating magnetic fields. The more the magnet’s magnetic field, the stronger the magnet is. There are usually various types of magnets, like horseshoe magnet, bar magnet and many more. It is responsible for inheriting one of the essential characteristics of any magnet, i.e., it produces a force that helps pull other ferromagnetic elements towards itself. Ferromagnetic materials like steel, iron, nickel, etc., apply an attraction or repulsion force on other magnets. The ferromagnetic material is the lone element attracted to any magnet so strongly; thus, it is called magnetic. All other elements respond weakly in the presence of any magnetic field. Such materials are further subdivided into two classes, “soft” and “hard materials. Soft materials cannot stay magnetised for a longer period, but hard materials can do so. 

What is Magnetic Dipole?

Magnetic moment of current carrying coil (or loop)

•   Current carrying coil(or loop) behaves like a magnetic dipole . The face of the coil in which current appears to flow ACW acts as the north pole while the face of the coil in which current appears to flow CW acts as the south pole .

• A loop of geometrical area A, carries a current I then its magnetic moment is given as M=IA

• For a coil of turns N, M=NIA. 

The magnetic dipole moment is defined as the torque experienced by a certain object in the presence of the magnetic field. The same magnetic field produces large torques in the case of larger magnets. The direction and strength of this torque depend on the degree of the magnetic moment and its locations concerning the direction of the magnetic field. The unit of a magnetic dipole in an electromagnetic system is centimetre–gram–second.

Magnetic Dipole- Theory

A string of representations can demonstrate the magnetic field, and each of them is a lot more complicated than the previous term. The first 3 terms are the monopole (represented by magnetic north or south poles), the dipole (represented by two opposite and equal magnetic poles), & the quadrupole (represented by four poles combining to construct two opposite and equal dipoles). To govern the first zero term at big distances, the magnetic field’s degree for each term decreases gradually with distance.

For most magnets, the magnetic dipole is the primary non-zero term. It is the border of a pair of the poles or a closed loop when the dimensions of sources drop down to 0, while the moment is kept continuously. These restrictions are the same as soon as they are applied to the fields far from the sources. 

How is magnetic dipole formed?

We learned a lot of magnetic dipoles now. Let’s see “How is magnetic dipole formed?” The spinning of electrons on their axis, the circulation of electrons around the atomic nuclei, and the rotation of positively charged atomic nuclei all are in the form of magnetic dipoles. The sum of all these effects may cancel, saying that the atom is not a magnetic dipole. If the effect doesn’t cancel out, the atom is a permanent magnetic dipole. Many millions of atoms come into the same alignment resulting in the formation of the ferromagnetic domain that constitutes a magnetic dipole. 

Magnetic Dipole Formula 

A magnetic field B, formed because of a current loop that has current I, is given by 

Currently, the loop area is 

A= πr²

Therefore, the formula of this magnetic field becomes,

The quantity μ is called the magnetic dipole moment. There is no charge counterpart in various electric fields, for example, a magnetic field. So there aren’t any sinks or sources to magnetic fields. In this case, it can only possess a dipole. The magnetic field possesses both sink and source that is both north and south poles. The magnetic dipole can be considered the fundamental unit to produce any magnetic field. The majority of elementary particles act as magnetic dipoles. 

A wire having ‘N’ turns in the loop, has a magnetic moment of: 

μ = NiA

Examples of Magnetic Dipole 

An example of a magnetic dipole is a bar magnet where one pole is called the North Pole, and another one is called the South Pole. Magnetic compass needles are yet another example of a magnetic dipole. Electrons circulating atomic nuclei, rotating positively charged atomic nuclei, and spinning electrons on their axes are magnetic dipoles.

Conclusion

A magnetic dipole is a tiny magnet equivalent to the flow of electric charge around a circular loop. Magnetic dipole moments have dimensions of current time area and energy divided by magnetic flux density. Studying a magnetic dipole and its magnetic dipole moment can be very specific. In many medical-related procedures and techniques, the magnetic dipole acts to be a primary factor. Nowadays, many new procedures and techniques of magnetism allow magnetic screening to address what is inside the human body eventually. Still, the magnetic dipole will remain an actively growing scientific field.