In a Young’s double-slit experiment, the slits are separated by 0.28 mm and the screen is placed 1.4 m away. The distance between the central bright fringe and the fourth bright fringe is measured to be 1.2 cm. Determine the wavelength of light used in the experiment.
Figure showing bright fringes in Young's double slit experiment
Given:
Distance between the slits (d) = 0.28mm
Distance between the slits and the screen (D) = 1.4m
Distance between the central bright fringe and fourth bright fringe (yn) = 1.2cm
where n is the order of the fringe, here, n = 4
λ = Wavelength of light used
From the formula,
λ = 142.8nm
Hence, the wavelength of light used is 142.8nm.
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