88) Two slits are made one millimetre apart and the screen is placed one metre away. What is the fringe separation when bluegreen light of wavelength 500 nm is used?

89) A viewing screen is separated from a double-slit source by 1.2 m. The distance between the two slits is 0.030 mm. The second-order bright fringe m =2 is 4.5 cm from the center line. Wavelength of the light is

90) A viewing screen is separated from a double-slit source by 1.2 m. The distance between the two slits is 0.030 mm. The second-order bright fringe m =2 is 4.5 cm from the center line. Distance between adjacent bright fringes is

91) A light source emits visible light of two wavelengths:???= 430 nm and??' = 510 nm. The source is used in a double-slit interference experiment in which L = 1.5 m and d = 0.025 mm. separation distance between the third order bright fringes. is

92) In a two-slit interference experiment in which the slits are 0.200 mm apart and the screen is 1.00 m from the slits. The m = 3 bright fringe is 9.49 mm from the central fringe. Wavelength of the light is