Magnet-Electromagnetism|electricaltechguru

Electromagnetism

In this section we will see about magnet, electromagnet and electromagnetisme,electromagnetic induction.

1.Magnet

A piece of solid substance which having a property of attracting a small pieces of material like iron, steel.
Below diagram of natural magnet is best example of these which attract small pieces of iron material.

There are two types of magnet:
1. Natural magnet
2. Electromagnet

2.Natural Magnet

Natural magnet having a natural property of attracting pieces of material like iron, steel etc.
In below diagram white pieces are iron material which attract by this magnet at the  N pole and S Pole.

Natural magnet

Natural magnet doesn't required in external energy create magnetic force like electromagnet.

3.Electromagnet

Electromagnet is form by passing electric current around certain material like iron.

Electromagnet

In above diagram ,when the current start flowing through this coil the metal act as a magnet.
 the magnetic action of the electromagnet present till electric current flows through the coil which ground around the solid material like iron. After stopping of electric current of the coil of electromagnet the magnetic energy of that iron is lost.

Properties of magnet

There are some important properties of magnet are as follows:

1. Magnet attract small pieces of iron.
2. Freely suspended magnet align itself in North-south direction

4.Magnetism

Whenever electric current flow through the conductor magnetic field produce surrounding that conductor. That means whenever the  electrons movement takes place in any conductor they will create the magnetism surrounding to that conductor.

5.Electromagnetic induction

When conductor cuts magnetic field EMF is get induced in that conductor and while connecting load across that coil or conductor current will start flow through this, that is called as electromagnetic induction.

6.Permeability

What the phenomenon of magnetism and electromagnetisme is basically depends on the property of material or property of medium. The medium through which magnetic flux is passed.

Permeability of any medium is of two types
1. absolute permeability
2. relative permeability

Absolute permeability

Absolute permeability of the material is defined as the ratio of magnetic flux density(B) to the magnetic field strength(H) which product that flux density.
The unit of absolute permeability is henry per meter  or Henry/meter.
Relative permeability of free space or vacuum is equals to 1.

Relative permeability

Relative permeability is defined as the ratio of flux densityB in particular medium produced by magnet to the flux density(B) in air or vacuum.

7.Electromotive force (EMF)

In electrical circuit electromotive force To flow of electron.
EMF is also called as volt which cause flow of electron.

8.Magnetomotive force(MMF)

The force responsible for flow flux is called as magnetomotive force (MMF).
MMF=N*I
Where,
N=number of turns of magnetizing c
I=current through a coil

9.Reluctance

The property of material to oppose the flow of magnetic flux is called as reluctance