An Electromagnetic Wave of frequency v = 3.0 MHz passes from vacuum into a dielectric medium with permittivity ε = 4.0. Them |
Wavelength is doubled and the frequency remains unchanged Wavelength is doubled and frequency becomes hal Wavelength is halved and frequency remains unchanged Wavelength and frequency both become unchanged |
Wavelength is halved and frequency remains unchanged |
In vacuum, $ε_0 = 1$ In medium,$ε = 4$ So, refractive index $ \mu = \sqrt{ε/ε_0} = \sqrt{4/1} = 2 $ wavelength $λ' = \frac{λ}{\mu}=\frac{λ}{2}$ and wave velocity $ v = \frac{c}{\mu}=\frac{c}{2}$ Hence, it is clear that wavelength and velocity will become half but frequency remains uncharged when the wave is passing through any medium. |