The following Topics and Sub-Topics are covered in this chapter and are available on MSVgo:
The motion of electrons in atoms gives rise to the concept of magnetism. Magnetism assists in understanding the behavioral property of matter. Various types of magnetic materials such as paramagnetic or diamagnetic rise, when a matter is placed in a magnetic field. Magnetism and Matter are very closely related to each other. Matter can be explained, as a substance that has mass and occupies space. A Matter can be categorized, like solid, liquid, and gas. The relation of magnetism with Matter is that magnetism studies the behavior of matter when placed on a magnetic field.
When a magnet is placed in a uniform magnetic field (B), a dipole moment (m) is experienced by a magnet (m). It experiences :-
The imaginary lines in a magnetic field are called Magnetic Field Lines. The region around a magnetic material or which shows moving electric charge within which magnetism force acts. The alternative way used to represent the information contained within a magnetic vector field is called Magnetic Field Lines.
The Properties of Magnetic Field Lines are:-
The Earth’s Magnetic field extends millions of kilometers into outer space. Although its extension is broad, and far in terms of field strength, It is very weak. The dynamo effect theory explains how Earth’s Magnetism is caused. Earth’s Magnetism is mainly happening due to the convection currents of molten iron and nickel in the earth’s core.
Components of Earth’s Magnetic Field
Abounds with the baffling, variety of elements and compounds the earth beside, have been combining new alloys, compounds, and even elements. As you know, the circulation electron in an atom has a magnetic moment and these moments add up vectorially, and they can give a net magnetic moment which is non-zero.
A system that involves a magnetic field, the hysteresis occurs there. Ferromagnetic substances properties entail hysteresis.
The explanation of Hysteresis Curve is, given below:-
Note – The Curve may vary from different materials like soft iron, steel, etc.
The magnetic lines of force are permitted to pass through a material. The representation is through μR = (B/Bo) = (μ/μo)
Bo – Magnetic lines number per unit in a vacuum
B – Number of magnetic lines of force per unit area in the given material
μ – Magnetic permeability of a material
μo – Magnetic permeability of free space
μR – Value for vacuum is one.
Magnetic permeability materials are:-
Diamagnetic substances are those on the external magnetic field that tends to move from stronger to the weaker part. The Resultant magnetic moment of an atom is zero in diamagnetic substances.
Paramagnetism substances get weakly magnetised when they are placed in an external magnetic field. They tend to move from a weak magnetic field to a strong magnetic field.
Ferromagnetic substances get strongly magnetised when they are placed in an external magnetic field. In a paramagnetic material, the individual atoms in a ferromagnetic material possess a dipole moment.
Magnetic Intensity means the degree at which a magnetic field magnetises a material. The Magnetic Intensity is several ampere-turns flowing round a unit length of a toroidal solenoid to produce that magnetic field in the solenoid. It can be shown by
H = n * current.
N – Number turns per unit length of a toroidal solenoid carrying current i. Vector quantity and its SI unit is Am‒1
Intensity Of Magnetisation
It simply means a magnetic moment per unit volume of the material. The formula is:-
I = Magnetic moment/ Volume = M/V
Magnetic Susceptibility is the ratio of the intensity of magnetisation (M) induced in the material to the magnetising force (H) applied to it. The formula for Magnetic Susceptibility:-
Formula – X = Magnetic Susceptibility/Field intensity
X – Magnetic Susceptibility
M – Magnetization
H – Field intensity
Magnetism and Matter is a phenomenon that has a significant role in almost every field of science. This chapter is very crucial, especially for your CBSE class 12 exams. Learn more about magnetism and matter with conceptual videos on the MSVgo app.