Light of wavelength 2400 x 10-10 m in air will become light of wavelength in glass (μ = 1.5)

equal to

A. 1600 x 10-10 m B. 7200 x 10-10 m C. 1080 x 10-10 m D. none of these

The speed of light in vacuum is equal to the product of the index of refraction and the speed of light through that substance. c = n1v1 = n2v2 , since the frequency is constant then the product of wavelength through a medium and its index of refraction in that medium is equal to its wavelength in new medium and its new index of refraction, n1x1 = n2x2. The answer is A, 2400/1.5 = 1600.