A double-slit apparatus is immersed in a liquid of refractive index 1.33. in It has slit separation of 1 mm and distance between the plane of slits and screen is 1.33 m. The slits are illuminated by a parallel beam or light whose wavelength in air is `6300 Å.`
a. Calculate the fringe width.
b. One of the slits of the apparauts is covered by a thin glass sheet of refractive index 1.53. Find the smallest thickness of the sheet to bring the adjacent minimum on the axix.

Answer

0.63 mm