1. The problem statement, all variables and given/known data I have a doubt about the current linkage, Θf, in figure 2.2b of a salient pole motor. In this textbook, the current linkage is expressed by ∫H⋅dl = Θf = ∑i. However, in the figure 2.2b between q(left) and q(right), how can the Θf be constant? Since, the author doesn't show how he chose the Amperian loop, how can I know how many currents are enclosed (∑i)? 2. Relevant equations ∫H⋅dl = Θf = ∑i 3. The attempt at a solution I have studied the application of Ampere's law to solenoids, which have the same type of winding as that on the rotor of a salient pole machine. I was trying to assume so many Amperian paths, trying to figure the 2.2b out.