Question

In medium with relative permittivity 1 and relative permeability 4, the speed of light is

(a) 1.5 x 10⁸ m/s

(b) 4.5 x 10⁸ m/s

(c) 5.5 x 10⁸ m/s

(d) 3.5 x 10⁸ m/s

Answer 1

(a) 1.5 x 10⁸ m/s

μ = √∈_r μ_r = √1 x 4 = 2

⇒ v = c/μ = 3 x 10⁸ /2

= 1.5 x 10⁸ m/s