[问答题]
Suppose a thin pieceuglf0b b;kj 4* of glass is pefqw.s d:z +b/laced in front of the lower slit in Fig. 24–7 so that the two waves enterfe.: /d+qswz b the slits 180$^{\circ}\,$ out of phase (Fig. 24–57). Describe in detail the interference pattern on the screen.
24-7
24-57