A monochromatic beam of light of wavelength `6000 A` in vacuum enters a medium of refractive index `1.5`. In the medium its wavelength is…., its frequency is…..

Options

A. `25xx10^(7)` per m
B. `25xx10^(6)` per m
C. `25xx10^(4)` per m
D. `25xx10^(8)` per m

Answer

B

Explanation

Refractive index of glass with respect to air is `._(a)mu_(g)=(lamda_(a))/(lamda_(g))`
or `(._(a)mu_(g))/(lamda_(a))=(1)/(lamda_(g))=overline(v)_(g)`
`thereforeoverline(v)_(g)=(1.5)/(6000xx10^(-10))`
`=0.25xx10^(7)`
`=2.5xx10^6`per min