[单选题]
A laser beam passes through a narrow
,4 nzbn6b )s)e6rklzm slit and incident on a scree
, 5ch8eyq0 pu+hadv8r9flg ih;zj: z. n. A diffraction pattern is observed on the screen. The variation of intensity
r:8zc;paf5yhj +g.qz,he8lv 9i0d hu$I$ of light on the screen with distance $x$ is seen in the graph below.
Which of the following graphs best represents intensity distribution with distance when the slit is replaced by one of greater width? The original distribution is shown with a dashed line.
A.
B.
C.
D.
参考答案:
A
本题详细解析:
Explanation:
A greater slit width allows more light to reach the screen. This increases the intensity. So the peaks will be higher. The angular width of maxima is proportional with $\frac{λ}{b}$. An increase of slit width b results in a decrease in angular width of the maxima. Angular width and width of maxima are proportional. Therefore, the maxima will be narrower.
