申論題

5. (10%) A uniform plane wave (UPW) is incident from free-space (μ₁ = μ₀,ε₁ = ε₀) onto a dielectric medium (μ₂ = μ₀,ε₂ unknown) at an oblique incident angle.

(2). Please find the value of ε₂ for which the critical angle for the total internal reflection =60°. (5%)