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

Options

A. Wavelength and frequency both become half
B. wavelength is doubled and frequency remains unchanged
C. wavelength and frequency both remain unchanged
D. wavelength is halved and frequency remain unchanged

Answer

d

Explanation

The frequency of electromagnetic wave remains unchanged
but the wavelength of em wave
changes when it passes from one medium to
another.
`c=1/(sqrt(mu_0in_0)) :. Cprop 1/(sqrt(in_0)) and vprop1/(sqrt(in))`
`:. c/v =sqrt((in)/(in_0))=sqrt(4/1)=2`
`c/v=(vlambda)/(vlambda')=lambda/lambda'=2 or lambda'=lambda/2`