Problem 1: In a Young’s double slit experiment the separation of the slits is 1 mm and red light of wavelength 620 nm is falling on it. Determine the distance between the central bight band and the fifth bright fringe on the screen which is 3 m away from the slit.
Incident wavelength (red light) = λ = 620 × 10-9m
No of bright fringes = m = 5
Distance in slits and screen = L = 3 m
Distance between central band and 5th fringe = Y =?
(Please note the perpendicular AD in the diagram is not that exact1)
Where Y is the distance between central point and 5th fringe which we want to find. Put the values,