Final answer:
The flux in the air gap of the magnetic circuit can be calculated using the formula Φ = B x A. By substituting the given values into the formula, the flux is approximately 2.402 x 10^(-6) Wb.
Step-by-step explanation:
To determine the flux in the air gap, we need to consider the fringing field extension and the magnetic properties of the core and air gap.
The square cross-sectional area of the core is 3cm x 3cm. The air gap is 0.1cm with a fringing field extension of 0.1cm beyond the square length. This means that the effective length of the air gap is 3.1cm.
The flux in the air gap can be calculated using the formula Φ = B x A, where B is the magnetic field and A is the area. The magnetic field can be determined using the formula B = µ0 x H, where µ0 is the permeability of free space and H is the magnetizing force.
Given that the magnetizing force is NI = 200 AT and the cross-sectional area is 3.1cm x 3.1cm, the flux in the air gap can be calculated by substituting these values into the formulas mentioned above.
Let's plug in the values and calculate:
µ0 = 4π x 10^(-7) T.m/A
B = µ0 x H = (4π x 10^(-7) T.m/A) x 200 AT = 2.5 x 10^(-4) T
A = 3.1cm x 3.1cm = 0.00961 m^2
Φ = B x A = (2.5 x 10^(-4) T) x (0.00961 m^2) = 2.402 x 10^(-6) Wb
Therefore, the flux in the air gap is approximately 2.402 x 10^(-6) Wb.