The frequency of a light wave is the same when the light travels in ethyl alcohol or in carbon disulfide. find the ratio of the wavelength of the light in ethyl alcohol to that in carbon disulfide. the refractive indices n of carbon disulfide and ethyl alcohol are ndisulfide = 1.632 and nalcohol = 1.362.

Ratio of wavelength will be 1.1982                    

Explanation:

We know that velocity in any medium is given by   , here c is the velocity of light and n is the refractive index

We know that wavelength is given by , from the relation we can see that wavelength is inversely proportional to the refractive index

We have given refractive index of carbon disulfide = 1.632

And refractive index of ethyl alcohol = 1.362

So ratio of wavelength of ethyl alcohol and carbon disulfide =

15.3 cos 65 degrees trig