Chapter 12, Problem 14P

a. Find the current I required to establish a flux $\text{Φ = 2}{\text{.4 × 10}}^{\text{-4}}\text{ Wb}$ in the magnetic circuit in Fig. 12.41.

b. Compare the mmf drop across the air gap to that across the rest of the magnetic circuit. Discuss your results using the value of $\mu$ for each material.