A monochromatic light of frequency 5×10¹⁴ Hz travelling through air is incident on a medium of refractive index 2. The wavelength of the refracted light is:
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Question

A monochromatic light of frequency 5×10¹⁴ Hz travelling through air is incident on a medium of refractive index 2. The wavelength of the refracted light is:

G1 Physics · Accepted Answer

Frequency does not change when light enters another medium. In air, λ₀ = c/f = (3×10⁸)/(5×10¹⁴) = 6×10⁻⁷ m = 600 nm. Inside a medium of refractive index μ = 2, the speed becomes c/μ, so the wavelength becomes λ = λ₀/μ = 600/2 = 300 nm. Correct option: A.