Page 506 - Basic Electrical Engineering

Figure 5.24

This is an example of a parallel circuit. As current in an electric circuit gets
divided into two parallel branches, the flux produced in the central limb will

get divided into the two outer limbs.
We will calculate the MMF required for the central limb as also for any of
the outer limbs which will maintain the desired flux in the core. For a flux

2
density of 1.2 Wb/m , the value of H has been given. Let us calculate the flux
density in the central limb first.

Flux density in the central limb,

The Flux density in the outer limb will be the same as that in the central
limb since half the flux is available in each of the outer limbs and their cross-
sectional area is half of that of the central limb.

2
The corresponding H i.e., AT/m for flux density of 1.2 Wb/m has been
given as 750.

The total MMF required = MMF required for the central limb + MMF
required for one outer limb (and not for both the limbs).
Since

Total MMF required