4 Find the mutual inductance between the following cur rents

4. Find the mutual inductance between the following cur- rents (a) Toroidal coil of rectangular or circular cross section coaxially centered about an infinitely long line current. Hint: tan. a +b cos x Va -b a +b r dr N turns N turns Toroid cross-section Toroid cross-vection

Solution

M=(mu0 x mu1 x N1 x N2 x A)/l

Where:

mu0 is the permeability of free space (4..10^-7)

mu1 is the relative permeability of the soft iron core

N is in the number of coil turns

A is in the cross-sectional area in m²

l is the coils length in meters

Putting the mu1 value 100, mutual inductance will raise by 100.