Answer
The B value is about 1.07 tesla
Work Step by Step
Given:
Bar of iron-silicon alloy within a coil of wire that is 0.40 m long, having 50 turns with a current of 0.1 A.
Required:
B field within the bar
Solution:
Using Equation 20.1:
$H = \frac{NI}{l} = \frac{(50 turns)(0.1 A)}{0.40 m} = 12.5 A/m$
From the given Figure 20.29, the B value is about 1.07 tesla.