1991B6. Light consisting of two wavelengths, λa=4.4×10−7 meter and λb=5.5×10−7 meter, is incident normally on a barrier with two slits separated by a distance d . The intensity distribution is measured along a plane that is a distance L=0.85 meter from the slits as shown above. The movable detector contains a photoelectric cell whose position y is measured from the central maximum. The first-order maximum for the longer wavelength λb occurs at y=1.2×10−2 meter.
a. Determine the slit separation d.
b. At what position Ya does the first-order maximum occur for the shorter wavelength λa ?
In a different experiment, light containing many wavelengths is incident on the slits. It is found that the photosensitive surface in the detector is insensitive to light with wavelengths longer than 6.0×10−7m.
c. Determine the work function of the photosensitive surface.
d. Determine the maximum kinetic energy of electrons ejected from the photosensitive surface when exposed. to light of wavelength λ=4.4×10−7m.
