Similar to the resistance characteristic in electricity, we have reluctance in magnetism which is the property of the substance that opposes the magnetic flux through it.
The reluctance of any part of a magnetic circuit may be defined as the ratio of the drop in magnetomotive force to the flux produced in that part of the circuit. It is measured in ampere-turns/Weber and is denoted by S.
Reluctance = m.m.f ⁄ flux
Reluctance = 30 ⁄ 15
Reluctance = 2 Amp-turns/Wb
EXAMIANS