An electromagnetic wave of frequency v = 3.0 MHz passes from vacuum into a dielectric medium with relative permittivity ε = 4.0. Then

Options

(a) wavelength is doubled and frequency is unchanged
(b) wavelength is doubled and frequency becomes half
(c) wavelength is halved and frequency remains unchanged
(d) wavelength and frequency both remain unchanged

Correct Answer:

wavelength is halved and frequency remains unchanged

Explanation:

Given : frequency f = 2 MHz, relative permitivity εᵣ = 4
For formula,
velocity v = c / √εᵣ = c / 2
λ’ = λ / 2
[since frequency remains unchanged ]