Example: Ampere's Law
Consider a toroid which has N = 50 turns. The toroid has an ID = 10cm and OD = 15cm. For a current i = 5A calculate the field intensity H along the mean path length within the toroid. (this problem is similar to Example 5-1 in the text book)
The magnetic field intensity Hm is constant along the circular contour because of symmetry.
The mean path length is
The mean path length isThe mean path length encloses the current i N-times.
From Eq. 5-1
One can assume a uniform Hm throughout the cross-section of the toroid because the width is smaller than the mean radius.