A light wave in air enters a medium of refractive index `(4)/(3)`. If the wavelength of light in air is `6000Å`, then the wave number of light in the medium is

Options

A. `1.1 xx 10^(6) m^(-1)`
B. `4.4 xx 10^(6) m^(-1)`
C. `2.2 xx 10^(6) m^(-1)`
D. `6 xx 10^(6) m^(-1)`

Answer

C

Explanation

`mu_(m) = (4)/(3), lambda_(a) = 6000 A^(@), bar(lambda)_(m) = ?`
`mu_(m) = (lambda_(a))/(lambda_(m))`
`:. bar(lambda)_(m) = (1)/(lambda_(m)) = (mu_(m))/(lambda_(a))`
`= (4)/(3 xx 6 xx 10^(-7))`
`= 2.2 xx 10^(6) m^(-1)`