Question

Increase the slit width to 1050 nm. What happens to the width of the central bright fringe? (Always remember to wait a few seconds for the simulation to catch up with the changes you made.)
a:The width of the central bright fringe becomes wider.
b:The width of the central bright fringe becomes narrower.
c:The width of the central bright fringe does not change.

Answer 1

Answer:

b.

Explanation:

In case of Single Slit, diffraction will occur.

Then In Single slit Diffraction, width of central fringe is

$x_c= 2D\lambda/a$

where D= distance b/w screen and slit

a= slit width

\lambda = wavelength

Thus if Screen width increases keeping other factors same then width of central fringe becomes narrower as

$x_c\propto 1/a$

On increasing the slit width the central bright fringe width The width of the central bright fringe becomes narrower.