Question

Monochromatic light of wavelength 600nm enters from air into glass medium of refracted index 1.5 . The wavelength of refracted light inside the glass is ​

Answer 1

Wave length of Mono chromatic light = λ = 600 nm = 600 x 10^-9 m

Speed of light in air, c = 3 × 10^8 m/s

Refractive index of glass μ = 1.5

Frequency of light independent of the property of the medium in which it is travelling.  

Hence, the frequency of the refracted ray in glass is same as the frequency of the incident or reflected light in air.

f = (c/λ)

= (3 x 10^8)/ (600 x 10^-9)

= (5 x 10^14) Hz

Therefore, Refracted frequency, ν = 5 ×10^14 Hz

Speed of light in glass is related to the refractive index of water as:

ν = (c/ μ)  

= (3 x 10^8)/ (1.5)

= (2 x 10^8) m/s

Wavelength of light in glass is given by the relation,

λ = (ν/f)

= (2 x 10^8)/ (5 x 10^14)

= (0.4 x 10^-6) m

= 400 nm