Answer
$ B_{0} = 0.0302 tesla $
Work Step by Step
Given:
0.25 m long coil with 400 turns
Current = 15 A
H = 24,000 A-turns-m
Required:
flux density in vacuum
Solution:
Using Equation 20.3:
$ B_{0} = μ_{0}H = (1.257 \times 10^{-6} H/m)(24,000 A-turns/m) = 0.0302 tesla $