Reading assignment: 38.1-38.2
As shown below, the diffraction pattern of a single slit has a broad maximum
in the middle, then narrower maxima to the sides. How does the intensity of the
broad middle peak compare to the intensity of the closest side peaks?
Broad peak is a lot more intense
Broad peak is a little more intense
Side peaks are a lot more intense
Side peaks are a little more intense
(You can see this from the expanded image now shown just below.)
This is the
diffraction pattern for a single wide slit. What will happen to the pattern
if the slit is made narrower?
If the slit is made narrower ("a" decreases), then the spacing between minima and maxima will increase. That is, the pattern will spread out.
This is the diffraction pattern for two wide slits. (a) What will happen here if
the distance between slits is made narrower? (b) What is the distance is held
constant but the width of each slit is made narrower.
(a) If the distance between slits is made narrower, the "fringes" (high frequency oscillation) will spread out, but the "diffraction minima" (low frequency oscillation) will stay in the same places.
(b) If the width of each slit is made narrower, the diffraction minima will spread out but the interference fringes will stay in the same places.