Red light of wavelength 6400 Å in air has a wavelength of 4000 Å in glass. If the wavelength of violet light in air is 4400 Å, then the wavelength in glass is

Explanation

`lambda_(r(glass))=(lambda_(r(air)))/(._(a)mu_(g))`
`4000=(6400)/(._(a)mu_(g))`
`._(a)mu_(g)=1.6`
`lambda_(r(glass))=(lambda_(r(air)))/(._(a)mu_(g))`
`lambda_(r(glass))=(4400)/(1.6)`
`=2750Å`.