1.STOP TO THINK 33.1 Suppose the viewing screen in Figure 33.4 is moved closer to the double slit. What happens to the interference fringes?a. They get brighter but otherwise do not change.b. They get brighter and closer together.c. They get brighter and farther apart.d. They get out of focus.e. They fade out and disappear.2. Equation33.6with:aHeNelaser(wavelength633nm),L=2m,d=1mm(thicknessofadime)andFigure33.4bequation= ym= m lambda L / d

iment. (b) 1. A plane wave is incident m = 4 on the double slit. 2. Waves spread out m = 3 behind each slit. m = 2 m = 1 m = 0 Central maximum m = 1 l the rlapped Top view of m = 2 ing in lark the double slit 3. The waves interfere in the m = 3 region where they overlap. .... 4. Bright fringes occur where the anti- m = 4 nodal lines intersect the viewing screen