An electromagnetic wave of frequency $3\times {10}^{6}Hz\left(3.0MHz\right)$ passes from vacuum into a non magnetic medium with permittivity,  $\in =16{\in }_0$, where ${\in }_0$ is the free space permittivity. The change in wavelength is

detailed solution

Correct option is C

when an electro magnetic wave travels from one medium to another medium its frequency remains constant but its velocity and wavelength will change.Speed of electronmagnetic wave in vacuum is  C=1μ0∈0=fλWhere 'f' is frequency and 'λ' is wavelength of electromagnetic wave.Speed of electromagnetic wave in a medium is C'=1kμ0∈0 where ‘K’ is dielectric constantC'=fλ' where λ' is wave length of electromagnetic wave in mediumDividing the two speeds we get fλ'fλ=1k ⇒λ'=λk ⇒λ'=λ∈∈0              ∴ k=∈∈0     ⇒λ'=λ16=λ4  Change in wavelength is  λ'−λ⇒λ'−λ=λ4-λ=−34λ=−34cf               ∴λ=cf   ⇒λ'−λ=−34×3×1083×106=-34×102 ⇒λ'−λ=−75 m