3. The ratio J/Ja (conduction current density to displacement current density) is very important at high frequencies. Calculate the ratio at 1 GHz for: (a) distilled water (u=μ, &=81, σ = 2×10 S/m) (b) sea water (μ=H₁, &=81, σ = 25 S/m) = (c) limestone (μ H₁, &=5, σ =2x10 S/m)