Question

If the relative permeability and relative permittivity of the medium is 1.0 and 2.25, respectively. Find the speed of the electromagnetic wave in this medium.

Answer 1

Relative permeability of the medium, μ_r = 1

Relative permitivity of the medium, ε_r = 2.25

`(epsilon_"r" = epsilon/epsilon_0 and mu_"r" = mu/mu_0)`

Speed of electromagnetic wave, v = `1/sqrt (mu epsilon)`

`= 1/sqrt(mu_"r"mu_0epsilon_"r"epsilon_0) = "C"/sqrt(mu_"r" epsilon_"r")`  ....`["where", "C" = 1/sqrt(mu_0epsilon_0)]`

`= (3 xx 10^8)/(sqrt(1 xx 2.25))`

`= (3 xx 10^8)/1.5`

v = `2 xx 10^8`ms^-1