A monochromatic beam of light in air has a wavelength of 427 nm in air.It passes through glass (n = 1.52)and then through carbon disulfide (n = 1.63).What is its wavelength in the carbon disulfide?
A)262 nm
B)696 nm
C)398 nm
D)458 nm
E)281 nm

Question

Quizplus · Accepted Answer

The wavelength of light changes when it passes from one medium to another due to the change in the speed of light. The speed of light in a medium is inversely proportional to the refractive index of the medium. Therefore, the wavelength of light in a medium is inversely proportional to the refractive index of the medium.In this case, the wavelength of light in air is 427 nm. The refractive index of glass is 1.52, and the refractive index of carbon disulfide is 1.63. Therefore, the wavelength of light in carbon disulfide is:$$\lambda_{cs} = \frac{\lambda_{air}}{n_{cs}} = \frac{427 	ext{ nm}}{1.63} = 262 	ext{ nm}$$Therefore, the correct answer is A.

A Monochromatic Beam of Light in Air Has a Wavelength