A Young's double slit apparatus is immersed in a liquid of refractive index `mu_(1).`
Channel: Doubtnut
Date: 02/08/2020

A Young's double slit apparatus is immersed in a liquid of refractive index `mu_(1).` The slit plame touches the liquid surface. A parallel beam of monochromatic light of wavelength `lambda` (in air) is incident normally on the slits.  a. Find the fringe width.  b. If one of the slits (say `S_(2)`) is covered by a transparent slab of refrative index `mu_(2)` and thickless t as shown, find the new position of central maxima.  c. Now, the other slit, `S_(1)` is also covered by a slab of same thickness and refractive index `mu_(3)` as shown in Fig. 2.49 due to which the central maxima recovers it positon, find the value of `mu_(3)`  Find the ratio of intensities at O in the three conditions (a), (b), and (c).