## Magnetic Flux Formula

Magnetic flux is defined as the total number of magnetic field lines through a given coil or area. It is the normal component of magnetic field which passes through the area. Magnetic flux is denoted by Î¦B where B represents magnetic field, and its unit is measured in Weber (Wb). The value of magnetic flux is a vector quantity and it depends on the direction of the magnetic field.

The magnetic flux formula is given by,

$\Phi_{B}\,&space;=\,&space;B.A$

$\Phi_{B}\,&space;=\,&space;BACos\theta$

Where,

B = magnetic field,

A = surface area and

Î˜ = angle between the normal to the surface and magnetic field.

Example 1

The Dimension of a rectangular loop is 0.50m and 0.60m. B and Î¸ are 0.02T and 45Â° respectively. Determine the magnetic flux through the surface.

Solution:

Given parameters are,

Dimensions of rectangular loop = 0.50m and 0.60m,

B = 0.02T,

Î¸ = 45Â°

Magnetic flux formula is given by

Î¦B = B A CosÎ¸

Area, A = 0.50 Ã— 0.60

Â Â Â Â Â Â Â Â Â Â Â Â = 0.3 m2

Î¦B = 0.02 Ã— 0.3 Ã— Cos 45

Â  = 0.00312 Wb

Example 2

The dimension of floor of a house is 20m by 15m. Vertical component of the magnetic field is 4.5 Ã— 10-5T, determine the magnetic flux.

Solution:

Given parameters are,

Dimensions of house = 20m by 15m,

B = 4.5Ã—10-5T,

Because it is a vertical component, Î¸ = 0Â°

Magnetic flux formula is given by,

Î¦B = B A CosÎ¸

Area, A = 20 Ã—15

Â Â Â Â Â Â Â Â  = 300 m2

Î¦B = 4.5 Ã— 10-5 Ã— 300 Ã— Cos 0

Â  = Â 1350 x 10-5 Wb