[单选题]
A laser beam passes thr
:ospr2kw xk 2y7sp(+eo-va*lv r,: tuough a narrow slit and incident o
.7rfnw;;u4u le-twcyo h3(rdn a screen. A diffraction patter
uc; w3tr uo7( e.-rn4hlwyd;fn is observed on the screen. The variation of intensity $I$ 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.
