A description of the magnetic reluctance, also discussing a way to calculate it
Key FactsGyroscopic Couple: The rate of change of angular momentum () = (In the limit).
- = Moment of Inertia.
- = Angular velocity
- = Angular velocity of precession.
Key facts The magnetic reluctance is defined as:
where is the magnetomotive force, and the magnetic flux. For a magnetic circuit of length , cross-sectional area , and relative magnetic permeability , the magnetic reluctance can be calculated with:
where is the magnetic permeability of free space. <br/> Constants
The magnetic reluctance of a magnetic circuit can be regarded as the formal analog of the resistance in an electrical circuit. The magnetic reluctance can be expressed as: Field Strength ). Furthermore, can be related to the magnetic flux density with the equation: 4) can also be written as: 3) becomes: 8) in (7), we get that: 10) becomes:
2), we get that can be calculated as:
Example - Magnetic flux and flux density of a toroid
Consider a toroid with the mean length of , the cross section of , and the relative magnetic permeability of . What is the magnetic flux and the magnetic flux density if the coil has 10 turns and the current is 2 amperes ?
As the magnetic reluctance is given by: 3), we obtain the magnetic flux: