The separation between the slits in Young’s double-slit experiment significantly affects the number and spacing of visible interference fringes on the screen:
- Increasing slit separation (d):
- The fringe width decreases, meaning the bright and dark fringes become closer together.
- This results in more fringes fitting within a given length on the screen.
- However, if the fringes become too closely spaced, they may become difficult to resolve or distinguish.
- Decreasing slit separation:
- The fringe width increases, so fringes are spaced farther apart.
- Fewer fringes fit on the screen, but each fringe is more easily observed.
- Number of visible fringes:
- A larger slit separation produces more closely spaced fringes, increasing the total number of fringes visible across the screen.
- Conversely, smaller slit separation leads to fewer, more widely spaced fringes.
In summary, larger slit separation leads to more fringes that are closer together, while smaller slit separation produces fewer, more widely spaced fringes. This affects how many fringes you can see clearly in the experiment.