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Two coherent sources are 0.18 mm apart and the fringes are observed on a screen 80 cm 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 lambda D)/(d)`. It is GIVEN that `D= 80 cm, d= 0.18 mm0.018 cm, y= 10.8 mm = 1.08 cm " and "n =4`. `THEREFORE lambda = (yd)/(nD)= (1.08xx 0.018)/(4xx 80)= 6075xx 10^(-8) cm= 6075 dotA`. |
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