1. By: Engr. Hinesh Kumar (Lecturer) MAGNETIC FLUX & MAGNETIC FLUX DENSITY

2. Definition Magnetic flux (most often denoted as Φ). The number of magnetic (flux) field lines which pass through a given cross-sectional area A. The SI unit of magnetic flux is the weber (in derived units: volt-seconds). The CGS unit is the Maxwell.

3. Explanation Consider an area ‘A’, placed in a magnetic field. Let this area is divided into small segments each of area  A. Flux through  A is the product of area and the normal component of field B, i.e

4. Cont… A = area of loop Φ= angle between B and the normal to the loop Now flux over whole area A is the sum of fluxes through all elements ∆A i.e.

5. Problem #1 Magnetic Flux A rectangular coil of wire is situated in a constant magnetic field whose magnitude is 0.50 T. The coil has an area of 2.0 m 2. Determine the magnetic flux for the three orientations,  = 0°, 60.0°, and 90.0°, shown below.

6. Magnetic Flux Density It is defined as the amount of magnetic flux in an unit area perpendicular to the direction of magnetic flow. The Magnetic Flux Density ( B ) is related to the Magnetic Field ( H ) by: μ is the permeability of the medium (material) where we are measuring the fields.

7. Cont… The magnetic flux density is measured in Webers per square meter [Wb/m^2], which is equivalent to Teslas [T]. The B field is a vector field, which means it has a magnitude and direction at each point in space. The constant μ is not dimensionless and has the defined value for free space, in henrys per meter (H/m), of