CBSE Class 12-science Answered

Q. In a single-slit diffraction experiment, the width of the slit is halved. The width of the central maximum, in the diffraction pattern, will become:

(a) half

(b) twice

(c) four times

(d) one-fourth

Solution:

Correct option - b: twice

In single-slit diffraction, if the width of the slit is reduced to half of its initial value, the width of the central maximum in the diffraction pattern will become twice. This is due to the fact that the width of the central maximum is inversely proportional to the width of the slit.

where x is the width of the central maximum in a single slit diffraction, D is the distance between the slit and the screen, is the light wavelength, and d is the slit width. 

Hence, when the slit's width is redacted to half, the central maximum expands, resulting in a doubling of its width.