Q71 / 75 · JEE Main 2025 (3 Apr Shift 2) · Physics
A monochromatic light of frequency $5 \times 10^{14} \mathrm{~Hz}$ travelling through air, is incident on a medium of refractive index ' 2 '. Wavelength of the refracted light will be :
- Correct answerA$300\mathrm{~nm}$
- B$600\mathrm{~nm}$
- C$400\mathrm{~nm}$
- D$500\mathrm{~nm}$
Solution
$\mathrm{f} \lambda=\mathrm{v} \quad \lambda_{\text {medium }}=\frac{\lambda_{\text {vacuum }}}{\mu}$
$\lambda_{\text {medium }} \Rightarrow \frac{3 \times 10^8}{2 \times 5 \times 10^{14}} \Rightarrow 0.3 \times 10^{-6} \Rightarrow 300 \mathrm{~nm}$
$\lambda_{\text {medium }} \Rightarrow \frac{3 \times 10^8}{2 \times 5 \times 10^{14}} \Rightarrow 0.3 \times 10^{-6} \Rightarrow 300 \mathrm{~nm}$
Hence, the correct answer is option: 'A'.