CBSE Class 12-science Answered
In a double slit experiment , a dichromatic light of wavelength 6500 A° and 5200 A° are used. What is the minimum distance from the central bright band at where the bright band of each of the colours will superpower? Given distance between two slits is (2×10^-3)m and distance between slits and screen is 1.2 m.
Asked by mridulabarua05 | 19 Feb, 2019, 11:54: AM
Expert Answer
Distance of nth bright fringe from centre = 
, where λ is wavelength of light used, D is slit-to-screen distance and d is distance between slits.
, where λ is wavelength of light used, D is slit-to-screen distance and d is distance between slits.if nth bright fringe of light of wavelength 6500 Aº coincides with the mth bright fringe of wavelength 5200 Aº, then we have
To have mimimum distance where bright fringes of both lights superimpose, we need to find mimimum numbers of n and m so that
the products (n×65) and (m×52) are equal. This is true if n = 4 and m = 5
hence minimum distance is 
Answered by Thiyagarajan K | 19 Feb, 2019, 02:20: PM
