Kevin Nash
Last Activity: 10 Years ago
Sol. M/B base H (found in the previous problem) = 3.75 *10^3 A-m^2 T^-1
θ = 37°, d = ?
M/B base H = 4π/μ base 0 (d^2 - ℓ^2)^3/2 tan θ
ℓ << d neglecting ℓ w.r.t.d
⇒ M/B base H = 4π/μ base 0 d^3 Tanθ⇒ 3.75 * 10^3 = 1/10^-7 * d^3 * 0.75
⇒ d^3 = 3.75 * 10^3 * 10^-7/0.75 = 5 * 10^-4
⇒ d = 0.079 m = 7.9 cm