Magnetisation & Magnetic Intensity: Definition and Differences

It is a fundamental concept that refers to the process through which material becomes magnetised. These materials then acquire a net magnetic moment. This phenomenon of magnetisation is important to understand how material respond to magnetic fields and their applications in technology and industry. 

Mathematically, magnetisation is expressed as:

$M = \frac{m_{\mathrm{net}}}{V}$

JEE Main exam and IIT JAM exam often ask questions related to this topic due to which it becomes important for students to learn this concept in detail. Magnetic intensity is also known as the magnetic field intensity is the measure of magnetic field strength. It is a vector quantity which is denoted by H. Magnetic field intensity describes the magnetic field created by electric currents and magnetic materials. It is related to magnetic flux density B through the equation:

B=μH

μ indicates magnetic permeability of material whereas in vacuum is permeability is ${\mu }_0$ .

${\mu }_0$ has the value $4 \pi \times {10}^{-7}$ henries per meter (H/m.

Magnetic intensity is generated either by electric currents that flow through conductors or by magnetic materials.

Magnetic Intensity in Free Space

In free space or vacuum, the magnetic intensity H is directly proportional to magnetic flux density B with proportionality constant since it is permeability of free space.

Magnetic Field Intensity in Magnetic Materials

Within magnetic materials, relationship between H and B is complex because of the magnetic material properties including Magnetisation M. Total magnetic flux density B in the material is given by:

$B = {\mu }_0 ( H + M )$

Here: 

M is the magnetization of material

The following table shows the difference between magnetic intensity and intensity of magnetisation in a tabular format. CUET exam and NEET exam students must learn about this: