# Describe magnetic flux or flux density

Publish On: 2019-04-24

Total Post: 559

# lala singh

Total Post: 22

## ANS: Describe magnetic flux or flux density

In a manner similar to that used for electric fields, the magnetic induction B can be represented by lines of induction B can be induction is a line so drawn that it everywhere parallel to the direction of all magnetic field. The lines of induction are called magnetic field ϕm. The selections of the number of lines to represent the magnetic induction quantitatively is arbitrary, and the choice made sets up the system of units to be used. The usual choice is to take the number of lines of induction per unit area passing through a surface perpendicular to the flux as equal to B. in the mks system a magnetic induction of 1N/A. m is represented by 1 line of induction per square meter. A line thus defined is called a Weber.

The magnetic induction B is the flux per unit area of the surface perpendicular to B, and hence magnetic induction is also called flux density. For a normal surface area ∆A

In the mks system flux density is measured in Weber’s per square meter. Form the way in which the Weber is defined, 1 Wb/m2 = 1N/A.m, and 1Wb = 1 N.m/A.

When cgs electromagnetic units are used, the lines of induction are selected so that the number of lines of induction per square centimeter of the area normal to the field is equal to B. The unit of flux thus defined is called the Maxwell. The corresponding unit of flux density, the Maxwell per square centimeter, is called the gauss; 1 g = 1ayn/abA.cm it follows that 1 wb/m2 = 104 g

In a uniform magnetic field the lines of induction are straight lines and uniformly spaced. For this type of field the flux through any plane area A is

ϕm = BA cos α

where α is the angle between B and the normal to the surface.