The refractive index of a certain glass is 1.5 for light whose wavelength in vacuum is 6000 Å. The wavelength of this light when it passes through glass is

Options

A. 4000 Å
B. 6000 Å
C. 9000 Å
D. 15000 Å

Answer

A

Explanation

`lambda prop (1)/(n) rArr (1)/(n) rArr (lambda_(a))/(lambda_(m)) = (n_(m))/(n_(a)) `
`rArr " " lambda_(m) = (6000)/(1.5) = 4000 Å.`