Two straight narrow parallel slis 0.2 mm apart are illuminated byp monochromatic light of wavelength `6000 overset(@)(A)`. Find the width of the fringe due to interference at a distance of 10 cm.

Two straight and narrow parallel slits 0.3 mm apart are illuminated by monochromatic light of wavelength 5900 Å .Find the width of fringe due to interference at a distance of 0.6 m from the slits.

In Young's experiment fringe width is 2 mm for light of wavelength 6000 overset(@)(A) . Calculate the fringe width if the entire apparatus is immersed in water of refractive idex 4/3.