Reluctance - Free MCQ Practice Test with solutions, GATE EE Basic Electrical

The reciprocal of reactance is permeance. It is the ability of a material to allow the passage of magnetic lines of flux.

The formula for reluctance is:
S= l/∫0 ∫rA.
From the formula, we can see that reluctance is directly proportional to the length of the material.

The formula for reluctance is:
S= l/∫0 ∫rA.
From the formula, we can see that reluctance is inversely proportional to the area of cross section of the material.

Reluctance is directly proportional to the length of the material hence as length increases, reluctance also increases.

Reluctance is inversely proportional to the area of cross section of the material hence as area increases, reluctance decreases.

Reluctance is the force per unit flux, hence its unit is A/Wb.

Resistance is the opposition to the flow of charge, similarly reluctance is the opposition to the flow of magnetic flux.

Reluctance is directly proportional to the strength of magnetic field, hence as the strength of magnetic field increases, the reluctance increases.

Reluctance is inversely proportional to the magnetic flux density, hence as magnetic flux density increases, reluctance decreases.

We know that:
F=phi*S
Substituting the given values from the question:
S=2A/Wb.