In a Young's double slit experiment , the interference fringes are obtained on screen `0.75` m apart . The third dark band is at a distance of `5.5` mm from the central fringes (i) Determine the wavelength of light used if the two slits are `0.15` mm apart , (ii) What will be the wavelength of light used if the entire apparatus is immersed in a liquid of refractive index 4/3 ?

Answer

(i) `4.4 xx 10^(-7)` m (ii) `3.3 xx 10^(-7)` m