## What is magnetic flux and its units

Hello friends, last time we have discussed about electric flux and its units. Similarly in magnetism, there is concept of magnetic flux. Have you imagined, why a magnet able to attract an iron piece place near by it but if the iron piece is placed somewhat far away from magnet then magnet is not able to attract it.

## Magnetic flux density

Magnetic flux density is also known as magnetic induction.

When a magnetic material is placed in an external magnetic field then material gets magnetized. Such magnetism produced in the material is called induced magnetism and the phenomenon is called is called magnetic induction

It is also defined as the number of magnetic lines of force inside a magnetized material crossing unit area normal to their direction.

Its S.I. units are weber per square meter.

## Magnetic Flux

The Magnetic flux Φ through any surface held in a magnetic field b is measured by the total number of magnetic lines of force crossing the surface

where d S = small area element through which line is passing.

Units

The S.I. unit of magnetic flux is weber (Wb). One weber is the amount of magnetic flux crossing over an area of 1 metre2 held normal to a uniform magnetic field of one tesla.

Thus                           1 weber = 1 tesla x 1 m2

The c.g.s. unit of Φ is maxwell (Mx),

where             1 weber = 108 maxwell