AAI ATC Junior Executive 2018 Shift 3 Paper

In a Fresnel's biprism arrangement, monochromatic light of wavelength 550 nm is used to obtain interference fringe pattern on the screen. When a thin, transparent glass sheet of refractive index 1.52 is introduced in the path of one of the interfering beams, ten interference fringes are found to be shifted. Then, the thickness of the glass sheet is nearly: