Wave Optics

JEE Main level, single correct, medium

4 of 191

Question 4 of 191

A monochromatic light of frequency 5×1014 Hz5 \times 10^{14} \mathrm{~Hz} travelling through air, is incident on a medium of refractive index ' 2 '. Wavelength of the refracted light will be :

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Answer: (A) 300 nm300\mathrm{~nm}

fλ=vλmedium =λvacuum μ\mathrm{f} \lambda=\mathrm{v} \quad \lambda_{\text {medium }}=\frac{\lambda_{\text {vacuum }}}{\mu}
λmedium ⇒3×1082×5×1014⇒0.3×10−6⇒300 nm\lambda_{\text {medium }} \Rightarrow \frac{3 \times 10^8}{2 \times 5 \times 10^{14}} \Rightarrow 0.3 \times 10^{-6} \Rightarrow 300 \mathrm{~nm}

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