Magnetic Flux
Brook Edgar
Teacher
Explainer Video
Magnetic Flux and Flux Linkage
Magnetic flux
Measures the number of field lines passing perpendicular through an area in Weber, Wb. It's a maximum when the plane of the coil is perpendicular to the field lines or when the normal is parallel to the field lines.
Formula:
Magnetic flux linkage
The total magnetic flux through N coils, measured in Weber-turns (Wb-turns).
Formula:
Remember: The angle is between the normal (perpendicular to the surface) and the magnetic field lines. This is the easiest way to determine the angle in exams. Always sketch the image below in exams as a reference. The magnetic flux here is a maximum if the coil is rotated through an angle theta clockwise so that the normal becomes parallel to the field lines.
Worked Example:
Calculate the magnetic flux of:
A rectangular loop, by in a uniform field of .
A single loop, radius in a field of at to the normal.
Answer:
Practice Question
A coil of wire is placed at an angle to a uniform magnetic field of flux density , as shown in the diagram with a cross-sectional area .
Calculate the change in flux linkage when the coil is rotated anticlockwise until .
-> Check out Brook's video explanation for more help.
Answer: