Single Slit Diffraction

Step 1: Understanding Double Slit Fraunhofer Diffraction
In the double-slit diffraction pattern, the fringe separation is given by the formula: Where:
is the wavelength of light,
is the distance from the slits to the screen,
is the separation between the slits.

Step 2: Effect of Changing the Slit Separation
If the slit separation is increased, the fringe separation will decrease, meaning the fringes will become closer together.
Conversely, if the slit separation decreases, the fringes will spread out.
Step 3: Conclusion Thus, when the separation between the slits is changed (increased), the fringe length will decrease.