The velocity of electromagnetic waves in a dielectric medium with relative permittivity of 4 will

Concept:

The velocity (V_p) of a plane electromagnetic wave is given as-

\({V_p} = \frac{1}{{\sqrt {μ \varepsilon } }}\)

Here, μ = μ_oμ_r

ε = ε_o ε_r

\({v_p} = \frac{1}{{\sqrt {{μ _o}{μ _r}{\varepsilon _o}{\varepsilon _r}} }}\)

\({v_p} = \frac{c}{{\sqrt {{μ _r}{\varepsilon _r}} }}\)-----(1)

\(c = \frac{1}{{\sqrt {{μ _o}{\varepsilon _o}} }} = 3 \times {10^8}\;m/sec\)

μ0 = permeability in free space 4π × 10^-7 H/m

εo = permittivity in free space 8.854 × 10^-12 C²/Nm²

Calculation:

Given:

μ_r = 4

From Equation (1):

\(v_p=\frac{3\times10^8}{\sqrt4}\)

v_p = 1.5 x 10⁸ m/sec