Magnetism and Matter

Introduction:
The poles of a bar magnet are comparable to those of an electric dipole's positive and negative charge. One pole is recognized as the north pole, while the other is designated as the south pole. These poles, when hanging freely, point roughly towards the geographical north and south poles. Poles that are similar repel one another, whereas poles that are dissimilar attract each other. A magnet's poles could never be divided. The tangent to a magnetic field line at any place defines the direction of the magnetic field at that location. A magnet's magnetic field lines create a close-knit circle. Magnetic field lines outside the core of the magnet go from the north pole to the south pole. There can be no crossing of magnetic field lines. This is because we may draw two tangents at the point of intersection. This would need the presence of two magnetic field directions at the same time, which is not conceivable. The intensity of the magnetic field is proportional to the number of field lines crossing per unit area. If a monopole is held at a given place, its magnetic field is equivalent to the magnetic force received by a unit pole strength. Our earth's magnetism was formerly thought to come from a massive bar magnet located deep within the planet along its rotational axis, but the fundamental argument against this hypothesis is that the interior of the planet is far too hot to sustain any magnetism. The structure of the earth's magnetic field changes with time and place. The solar wind has the greatest impact on this.

List of topics according to NCERT and JEE Main/NEET syllabus:

• Bar Magnet
• Magnetic Field Lines
• Torque on a Magnetic Dipole in Uniform Magnetic Field
• Work done in Rotating a Magnetic Dipole in Uniform Magnetic Field
• Earth’s Magnetism
• Magnetic Inclination or Dip
• Magnetisation
• Magnetic Susceptibility
• Magnetic Properties of Materials
• Diamagnetism
• Ferromagnetism
• Paramagnetism
• Curie’s Law
• Curie-Weiss law

Related Topics,

Important concepts and Laws:

The magnetic axis is the line connecting the two poles of a magnet, and the magnetic meridian is the vertical plane running through the axis of a freely suspended or pivoted magnet. The notion of lines of force was first suggested by Michael Faraday. A line of force, according to him, is an imaginary curve whose tangent at a location determines the direction of the field at that place. Magnetic force lines are closed curves. Lines of force outside a magnet go from north to south pole, whereas within they run from south to north.No lines flow through the space within a soft iron ring when it is put in a magnetic field. "Magnetic screening" or "Shielding" is the term for this occurrence.

The Law of Curie - The susceptibility of a paramagnetic material to magnetic fields is inversely related to the absolute temperature T.

The law of Curie-Weiss - A ferromagnetic substance becomes an ordinary paramagnetic substance at temperatures above the Curie temperature, and its magnetic susceptibility obeys the Curie-Weiss equation. Diamagnetic materials become weakly magnetised in the opposite direction of the magnetising field. In the direction of the magnetising field, paramagnetic substances become weakly magnetised. Ferromagnetic Substances: When put in a magnetising field, these substances become highly magnetised in the direction of the field. The magnetic field lines of the earth resemble a magnetic dipole at the planet's centre. The north magnetic pole is located near the geographic north pole, whereas the south magnetic pole is located near the geographic south pole

NCERT Notes Subject wise link:

• NCERT Notes for class 12 Physics.
• NCERT Notes for class 12 Chemistry.
• NCERT Notes for class 12 Mathematics.
• NCERT Notes for class 12 Biology.

Importance of magnetism and matter class 12

A significant chapter in Physics deals with magnetism and matter. When the matter is subjected to magnetism, it responds in a certain way. The production of a variety of magnetic materials is triggered by the presence of a magnetic field. Magnetism And Matter Class 12 goes into much detail on every topic related to magnets. The chapter on magnetism and matter is crucial for CBSE students' exams. The fundamental principles covered in this chapter serve as a foundation for more advanced subjects. It is critical that these notions are understood from the start. Not only for the CBSE students class 12 physics ch 5 magnetism and matter is important but it also has a heavy weightage in NEET and JEE. it becomes an important chapter because it has a lot of theory about which direct questions are asked so it becomes an easy score topic

• NCERT solutions for class 12 physics chapter magnetism and matter
• NCERT exemplar solutions for class 12 physics chapter magnetism and matter
• NCERT notes for class 12 physics chapter magnetism and matter

NCERT Solutions Subject wise link:

• NCERT solutions for class 12 Physics.
• NCERT solutions for class 12 Chemistry.
• NCERT solutions for class 12 Mathematics.
• NCERT solutions for class 12 Biology.
  

NCERT Exemplar Solutions Subject wise link:

• NCERT exemplar solutions for class 12 Physics.
• NCERT exemplar solutions for class 12 Chemistry.
• NCERT exemplar solutions for class 12 Mathematics.
• NCERT exemplar solutions for class 12 Biology.