The figure shows the cross section of a toroid with a rectangular cross-section. The inner and
outer radii of the toroid are Ri and R, and h is the height of the toroid. The coil consist on N
turns and the core has a permeability . The H-field lines and current i flowing through the
toroid are shown.
a) Apply Ampere's law to find the magnetic field intensity as a function of the distance r. Where r is the distance from the central axis of the toroid: 1) For r< R in the air.
2) For R< r < R inside the toroid.
3) For > R in the air.
b) Use the infinitesimal area element da = h dr shown to find the flux in the core. c) Find the inductance L using the flux linkage
a