Four relations have been given. Select the correct relation?

• A. MMF = Flux/Reluctance
• B. Flux = MMF/Permeance.
• C. MMF = Flux/Reluctance
• D. MMF = Flux/Permeance

Answer: (D)

The amount of flux produced by the magnet indicates the strength of the magnet. The more the magnetizing force (MMF), the more is the flux produced. The more the opposition to the flux path (i.e., reluctance or magnetic resistance) less is the flux produced. This relationship is expressed as
Flux = MMF/ Reluctance
Reluctance is the opposition offered by the material in the flux path to the establishment of the flux. The reluctance in a magnetic circuit is similar to the resistance in an electric circuit. Reluctance is the inverse of permeance.
MMF = Flux/Permeance