Flux Calculator
Magnetic flux through an area.
Formula first
Overview
Magnetic flux is a measurement of the total magnetic field passing through a specific surface area. In this fundamental form, it assumes a uniform magnetic field lines up perpendicularly to the surface plane.
Symbols
Variables
B = Magnetic Flux Density, A = Area, = Magnetic Flux
Apply it well
When To Use
When to use: This formula applies when the magnetic field B is constant over the entire area A. It is specifically used when the angle between the magnetic field and the surface normal is zero degrees, meaning the field is perpendicular to the surface.
Why it matters: Understanding flux is essential for Faraday's Law, which explains how moving magnets generate electricity in power plants. It is the core principle behind the operation of transformers, electric motors, and induction chargers.
Avoid these traps
Common Mistakes
- Using total surface area instead of projected area.
- Mixing cm² and m².
One free problem
Practice Problem
A circular wire loop has a surface area of 0.05 m². If a constant magnetic field of 0.4 Tesla passes perpendicularly through the loop, what is the resulting magnetic flux?
Solve for: Phi
Hint: Multiply the magnetic field strength by the cross-sectional area.
The full worked solution stays in the interactive walkthrough.
References
Sources
- Halliday, Resnick, Walker, Fundamentals of Physics
- Wikipedia: Magnetic flux
- Britannica: Magnetic flux
- NIST Special Publication 330 (2019), The International System of Units (SI)
- IUPAC Gold Book, 'magnetic flux density'
- IUPAC Gold Book, 'magnetic flux'
- Halliday, Resnick, Walker, Fundamentals of Physics, 11th ed., John Wiley & Sons
- Wikipedia: Earth's magnetic field