In Youngs double slit experiment using monochromatic light, the fringe pattern sgifts by certain distance on the screen when mica sheet of refractive index 1.6 and thickness 1.964 microns is introduced in the path of one of the interfering waves. The mica sheet is then removed and the distance between the slits and screen is doubled. It is found that distance between successive maxima now is same as the observed fringe shift upon the introduction of the mica sheet . Calculate the wavelength of monochromatic light used in experiment