Magnetic Permeability

In 1885, Oliver Heaviside introduced the term magnetic permeability, which is described as electromagnetism permeability, a property of a magnetic material that supports magnetic field formation. It monitors and evaluates the amount of magnetic flux supported by the material that can easily pass through it. Magnetic permeability is denoted by μ and is the scalar quantity.

This article on magnetic permeability provides Magnetic Permeability Definition in physics, factors affecting magnetic permeability, its various types and other related topics in detail. So, without any further do, let’s get started! 

What is Magnetic Permeability? 

Magnetic permeability is referred to as the ratio of magnetic intensity to magnetic induction. Magnetic permeability is denoted by μ and is the scalar quantity. Permeability of Medium is used to measure the resistance of the material to the magnetic field and the degree to which the magnetic field can actually penetrate through the material. In case the material has a larger magnetic permeability, the conductivity will be higher. 

Factors Affecting Magnetic Permeability 

There are several factors that directly or indirectly affect the magnetic permeability of a material. These factors can be the nature of the material, humidity, position in the medium, temperature and frequency of the applied force. Depending on the magnetic field, the magnetic permeability of a material can vary; however, it is always positive. Note: magnetic reluctivity is termed as the opposite of Permeability of Medium. Newtons per ampere squared (N/A2) or henry per metre (H/m) is the SI unit of magnetic permeability. 

Magnetic Permeability Formula,

Here is the formula of magnetic permeability – 

Magnetic permeability (μ) = B/H

Here, H = magnetising field and B = magnetic intensity. 

Types of Magnetic Permeability 

There are mainly three different types of magnetic permeability. These are as follows –

• Permeability for free space 

The other name of permeability for free space is the permeability of air or vacuum. It can be represented by μ0 = B0/H.

• Permeability for medium 

It refers to the magnetic intensity ratio in the magnetising and medium field. It is written as μ = B/H. 

• Relative permeability

Relative permeability can be described as dimensionless quantity. Since Relative permeability is the ratio of two different quantities but similar units, it does not have any unit of itself. Relative permeability is expressed as μr = μ/μm. 

Magnetic Permeability Materials 

Three types of magnetic permeability materials are as follows – 

• Paramagnetic materials 

The paramagnetic substances are those that get weekly magnetised if placed outside the magnetic field, the same as the direction of the externally applied field. The typical examples of paramagnetic substances are tungsten, aluminium, calcium, lithium, platinum, etc.

• Diamagnetic materials 

The diamagnetism substances are referred to as those substances, which hold the ability to move from a stronger part of a magnetic field to the weaker section. Some common examples of diamagnetism are antimony, bismuth, copper, lead, silicon, gold, silver and mercury. 

• Ferromagnetic materials 

Ferromagnetism or Ferromagnetic substances get magnetised strongly in the same direction as the externally applied field. Ferromagnetic substances examples are cobalt, iron and nickel.

What is Magnetism? 

The magnet has the property to repel or attract other substances, referred to as magnetism. When two bar magnets are positioned close to one another, the same poles will repel each other; however, the opposite poles will attract. The primary reason behind this behaviour of the magnet is the imaginary magnetic line that continuously revolves around. 

Explain Magnetic Field

Similar to the gravitational field, the magnetic field cannot be touched or seen. The pull of the earth’s gravitational field can only be felt on the objects around us and even on ourselves. The existence of magnetic fields can be determined by their effects on different objects such as pieces of metals, copper coil carrying the electric current and lodestone, a naturally magnetic rock. 

Imagine tiny iron pieces or filling sprinkled on a white paper along with a magnet bar in between. Every time the paper is tapped, the iron filings will be aligned around the magnet bar. Some of the properties of the magnetic field lines are- 

• The magnetic field lines do not have an intersection point.
• The magnets’ magnetic field lines build a continuous closed loop.  
• The more the magnetic field lines, the stronger the magnitude. 

Conclusion 

In this study material on magnetic permeability, we discussed the ratio of the magnetic intensity to the magnetic induction. Magnetic permeability is denoted by μ and is a scalar quantity. It is used for measuring the resistance of the material to the magnetic field and measuring the degree to which the magnetic field can actually penetrate through the material. Here, we briefly gave magnetic permeability definition, magnetic permeability formula, types of Magnetic permeability. We also discussed magnetism and magnetic fields.