tual inductance we solved for was found to be 6 h. The total inductance between A and B is:

Lt = L1 + L2 + 2M

Lt = 16 + 4 + (2 X 6)

Lt = 32 h

If you reverse the connections of one of the coils as shown in figure 4-11, the fields will have a canceling effect. The

formula for total inductance in that case is:

Lt = L1 + L2 - 2M.

To the illustrative example, this would change our total inductance between A and B from 32 h to:

Lt = 16 + 4 - (2 X 6)

Lt = 8 h.

Another factor affecting coupling is the angle at which the flux of one coil cuts that of another coil. If you pivot L2

(figure 4-12) at the center, you will find that the M reduces to zero at 90 and actually subtract from the total