# Suppose you added to the single slit an identical slit a distance d = 0.25mm away from the first....

## Question:

Suppose you added to the single slit an identical slit a distance d = 0.25mm away from the first. Draw the resulting interference pattern you might expect on the same screen. What happens when we increase the distance between slits? What happens in the limit that d becomes arbitrarily large?

## Interference Pattern:

The interference of light is the phenomenon of redistribution of intensity of light wave due to superposition of two wavelets originating from a single source. When two sources are derived from a single source they are coherent. The light sources which have constant or no phase difference between them are called the coherent source.

Position of mth fringe in the interference pattern is given by

{eq}y= m \dfrac{D \lambda }{d} {/eq}

Fringe width

{eq}W= \dfrac{D \lambda }{d} {/eq}

When the distance 'd' between the slits is increased, the fringe width decreases. 