In young's double slit experiment the slits are illumated by light of wavelength `5890^(@)` A and the distance between the fringes obtained on the screen is `0.2^(@)`. If the whole apparatus is immersed in water then the angular fringe width will be, if the refractive index of water is `4//3`

Options

A. `0.30^(@)`
B. `0.15^(@)`
C. `15^(@)`
D. `30^(@)`

Answer

B

Explanation

`w_(a)=lamda//drArrw_(a)alphalamda`
`((w_a)_("water"))/(w_(a))=(lamda_("water"))/lamda=lamda/(mu_("water")lamda)`
`(w_a)_("water")=(2xx3)/4=0.15^(@)`.