A monochromatic light beam of wavelength λ is diffracte
- q (i5kg;gwqrq9o0 ts*9ta jm-u- lnrd at a single slit of width
ikj -s-ou9 g;rawrtlq *mt5 (0 g-qnq9$b$. After passing the slit, a diffraction pattern is observed on a screen a large distance away. The width of the central maximum is $w$.
The screen is moved closer to the slit. Which of the following changes, done separately, could result in no change in $w$?