Calculate values for H , B , and M at = c for

Calculate values for H_ϕ, B_ϕ, and M_ϕ at ρ = c for a coaxial cable with a = 2.5 mm and b = 6 mm if it carries a current I = 12 A in the center conductor, and μ = 3μH/m for 2.5mm < ρ < 3.5 mm, μ = 5μH/m for 3.5mm < ρ < 4.5 mm, and μ = 10 μH/m for 4.5mm < ρ < 6 mm. Use c =:

(a) 3 mm;

(b) 4 mm;

(c) 5 mm.