In a single slit diffraction, the width of slit is 0.5 cm, focal length of lens is 40 cm and wavelength of light is 4890. The distance of first dark fringe is (Assume f=D)
Answer (1)
30th Jun, 2020
Hey
Minima
a sinθ = nλ ; n =1 and x/f = λ/a
Therefore, with given parameters x = 3.912 * 10^-5 m
Maxima
a sinθ = (2n+1)λ/2 ; n = 1 and sinθ = x/f
x =f3λ/2a
Therefore; x = 5.868 * 10^-5 m
Hence, distance between fringes;
x = x - x
5.868*10^-5 - 3.912 * 10^-5 m = 1.956 * 10^-5 m
For further doubts, ask us.
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