104) In Young's double-slit experiment using monochromatic light of wavelength l, the intensity of light at a point on the screen where path difference is??, is K units. What is the intensity of light at a point where path difference is???/3?

105) A beam of light consisting of two wavelengths, 650 nm and 520 nm, is used to obtain interference fringes in a Young's double-slit experiment. Find the distance of the third bright fringe on the screen from the central maximum for wavelength 650 nm.

106) A beam of light consisting of two wavelengths, 650 nm and 520 nm, is used to obtain interference fringes in a Young's double-slit experiment. What is the least distance from the central maximum where the bright fringes due to both the wavelengths coincide?

107) In a double-slit experiment the angular width of a fringe is found to be?0.2^??on a screen placed 1 m away. The wavelength of light used is 600 nm. What will be the angular width of the fringe if the entire experimental apparatus is immersed in water? Take refractive index of water to be 4/3.

108) What is the Brewster angle for air to glass transition? (Refractive index of glass = 1.5.)