Measuring the Total Magnetic Field
While Magnetic Field ($B$) measures the density of magnetic lines at a single point, Magnetic Flux ($\Phi$) measures the total magnetic field passing through a specific surface area.
Think of magnetic field as the intensity of rain falling, and magnetic flux as the total amount of water caught in a bucket. The amount of flux depends on:
- Field Strength ($B$): Stronger magnets produce more flux.
- Area ($A$): A larger loop will catch more magnetic field lines.
- Orientation ($\theta$): If the loop is tilted, it catches fewer lines. If the loop is parallel to the field lines, the flux is zero.
The Formula
Where:
=
Magnetic Flux (Webers, Wb)B=
Magnetic Field (Tesla, T)A=
Surface Area (m²)=
Angle between field and normal to surfaceExample Calculation
A flat square loop with an area of $0.1 , \text{m}^2$ is placed in a uniform $0.5 , \text{T}$ magnetic field. The loop is tilted at $60^\circ$ relative to the field lines.
- Calculate Cosine: $\cos(60^\circ) = 0.5$.
- Multiply: $0.5 \times 0.1 \times 0.5 = 0.025 , \text{Wb}$.
The total flux through the loop is $25 , \text{mWb}$ (milliwebers).