Chapter 12, Problem 21P

Note how closely the B-H curve of cast steel in Fig. 12.7 matches the curve for the voltage across a capacitor as it charges from zero volts to its final value.

a. Using the equation for the charging voltage as a guide, write an equation for B as a function of $HH[B=f(H)]$ for cast steel.

b. Test the resulting equation at $H=\text{ 900 At/m 1800 At/m, and 2700}$ At/m.

c. Using the equation of part (a). derive an equation for H in terms of $BB[H\text{ = }f\left(B\right)]$.

d. Test the resulting equation at $B\text{ = 1 T and }B\text{ = 1}\text{.4 T}$.

e. Using the result of part (C). perform the analysis of Example 12.1, and compare the results for the current I.