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An electromagnetic wave of frequency passes from vacuum into a non magnetic medium with permittivity, , where 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 mSimilar Questions
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