Physics

# Magnetism

## Magnetism

Magnetism is one aspect of the combined electromagnetic force. It refers to physical phenomena arising from the force caused by magnets, objects that produce fields that attract or repel other objects.

### Types of Magnets

Magnet is of two types:

• Natural Magnet.
• Artificial Magnet.

#### Natural Magnet

A substance called magnetite (iron ore) found in nature that attracts a piece of iron towards it is called Natural Magnet.

#### Artificial Magnet

A magnet made by humans by artificial methods is called Artificial Magnet.

Artificial magnets are made of soft iron or steel.

### Magnetic Field Intensity

In the field, such a conductive wire of length of the field in which the current of current is flowing, the force on the conductor is called the intensity of the field.

The intensity of a field is a vector amount whose unit is newton / ampere-meter or beaver / meter2 or tesla.

### Magnetic Force Lines

The imaginary lines in the magnetic field that display the direction of the magnetic field in that location are called magnetic force lines.

#### Properties of Magnetic Force Lines

The magnetic force lines originate from the north pole of the magnet and enter the south pole forming a curve, and then return to the north pole, passing through the magnet. Two magnetic force lines never intersect. The magnetic force lines of the same magnetic field are mutually and equally spaced.

### What is a Magnetic field?

The region around the magnet in which the other magnet experiences attraction or repulsion is called a magnetic field.

S.I. of magnetic field The unit is the taxa (T).

### What are the types of Magnetic Materials?

There are 03 types of magnetic materials:

• Paramagnetic Substance.
• Diamagnetic Substance.
• Ferromagnetic Substance.

#### Paramagnetic Substance

Substances that are slightly magnetized in the direction of the external magnetic field and tend to move from a weak magnetic field to a strong magnetic field are called Paramagnetic Substance. Such as sodium, aluminum, oxygen, etc.

#### Diamagnetic Substance

Substances that have a tendency to move from a strong magnetic field to a weak magnetic field and become slightly magnetized in the opposite direction of the external magnetic field are called diamagnetic substances. Such as salt, water, bismuth, etc.

#### Ferromagnetic Substance

Substances that are strongly magnetized in the direction of the external magnetic field and rapidly degrade from weak to strong magnetic fields are called Ferromagnetic Substance. Such as iron, cobalt, nickel, etc.

### What is Declination Angle?

The angle formed between meridians and post-magnetic meridians at a place is called Declination Angle.

### What is the Domain?

The numerous and subtle structures of atoms found within iron magnetized materials are called domains. The magnetic properties of substances are due to the domain itself.

Atoms from 1018 to 1021 are found in a domain.

### What is the Curie Temperature?

The temperature at which an iron magnet is converted into a magnetized material is called Curie Temperature.

The Curie heat is 3580C for nickel and 7700C for iron.

### What is an Electromagnet?

The barrels of malleable iron is called electromagnets.

The electromagnet is used in making dynamo, telephone, electric bell, wire communication, transformer, etc.

### What is Electromagnetic Induction?

The process by which current flows in a variable magnetic field in a conductor is called electromagnetic induction.

### What is Fleming’s left hand rule?

If the index finger, middle, and thumb of the left hand are stretched in such a way that they are perpendicular to each other. If the index finger shows the direction of the field and the middle current, then the thumb indicates the direction of motion of the conductor.

### What is Fleming’s right hand rule?

If the right hand index, middle, and thumb are stretched in such a way that they are perpendicular to each other. If the index finger indicates the direction of the field and the thumb indicates the direction of motion of the conductor, in such a case, the median represents the direction of current induced in the conductor.