Magnetic flux & Magnetic flux density

Magnetic flux & Magnetic flux density By: Engr. Hinesh Kumar (Lecturer)

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). • TheCGS unit is the Maxwell.

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

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.

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 m2 . Determine the magnetic flux for the three orientations, f = 0°, 60.0°, and 90.0°, shown below.

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.

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

Magnetic flux & Magnetic flux density