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Two coherent sources are 0.18 mm apart and the fringes are observed on a screen 80cm away. It is found that with a certain monochromatic source of light, the fourth bright fringe is situated at a distance of 10.8 mm from the central fringe. Calculate the wavelength of light. |
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Answer» Solution : The distance of the nth fringe from the central fringe is `y =(n lamda D)/(d)` It is GIVEN that D = 80cm, d = 0.18mm=0.018cm, y = 10.8mm = 1.08 CM and n=4. ` therefore lamda = (YD)/(nD) = (1.08 xx 0.018)/(4 xx 80) = 6075 xx 10^(-8) cm = 6075Å` |
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