Answer:
The width of the central bright fringe becomes narrower.
Step-by-step explanation:
In case of Single Slit, diffraction will occur.
Then In Single slit Diffraction, width of central fringe is
![x_c= 2D\lambda/a](https://img.qammunity.org/2021/formulas/physics/college/y4gv6wjgdy9hrrav4ovcaaqqumx37k119l.png)
where D= distance between screen and slit
a= slit width
![\lambda = wavelength](https://img.qammunity.org/2021/formulas/physics/college/y9ma3kubishg4densq95qb7l1unvrwq1op.png)
Thus if Screen width increases keeping other factors same then width of cental fringe becomes narrower as
![x_c\propto 1/a](https://img.qammunity.org/2021/formulas/physics/college/h4nqj5x54d4y66ckymti2jemiw5u9gzja6.png)
The width of the central bright fringe becomes narrower.