In a laboratory, a student observes that the distance between successive bright fringes on the screen is 0.25mm when monochromatic light of wavelength 500nm passes through a double–slit. The screen is 1.0m away from the slits.
(a) Calculate the slit separation used in this observation.
(b) The screen is then moved an additional 20cm away from the slits. Determine the new fringe width that will be obtained without altering any other parameter.
(c) To restore the original fringe width while the screen remains in its new position, the experimenter decides to adjust only the slit separation. Compute the value of the new slit separation required.