A Young's double slit apparatus is immersed in a liquid of refractive index 1.33. It has slit separation of 1 mm and interference pattern is observed on the screen at a distance 1.33 m from plane of slits. The wavelength in air is 6300A˚.
Calculate the fringe width.
a. 0.63 mm
b. 1.26 mm
c. 1.67 mm
d. 2.2 mm