Question

Define Magnetization. Write its SI unit and dimensions.

Answer 1

Hint: Here, we have to define magnetization and how magnetic polarization creates the density of permanent or induced magnetic dipole moments in a magnetic material and the strength of the pole. Also the magnetic dipole moment between the two poles of a magnet. State its dimensions and S.I. unit.

Complete step by step solution:

Firstly, we have to define the magnetic north pole and South Pole of a magnet. A device which has a magnetic north pole and South Pole on opposite sides is known as a magnetic dipole. It can be a bar magnet, a bar electromagnet, a current carrying ring or a solenoid etc.

In classical mechanics, Magnetization or magnetic polarization is the vector field that expresses the density of permanent or induced magnetic dipole moments in a magnetic material. The origin of the magnetic moments responsible for magnetization can be either microscopic electric currents resulting from the motion of electrons in atoms, or the spin of the electrons or the nuclei. Net magnetization results from the response of a material to an external magnetic field.

The strength of a pole of a dipole is called pole strength. Its SI unit is Ampere meter $\left ({Am} \right)$. And it is denoted by M.

In any dipole the pole strength of both the poles are always equal. The product of the strength of one of the poles and the distance between the poles is known as magnetic dipole moment. It is denoted by M and its SI unit is $A {m^2} $ 

When a magnetic material like iron is placed in a magnetic field, it gets a magnetic dipole moment. The magnetic dipole moment acquired per unit volume is known as Magnetization. 

Its SI unit will be $\dfrac{{A{m^2}}}{m}$  =Am .

Its dimension is ${{L^1} {M^0} {T^0} {A^1}}$ 

Note: Here, we need to take care while writing the dimensional formula and write the proper units and use the capital letters in square brackets. Remember the definition of magnetization then you approach the final answer.