Question

Please answer the question below with complete explanation.
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**$$Q: You are testing a setup where a laser shines on two slits and projects an interference pattern onto a distant screen. You find that the fringe pattern is too small to see clearly, so you need to change the setup somehow. Name Two Things you could alter that would make the fringe pattern more spread out on the screen.

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Answer 1

Width of a interference pattern is given by

 where,

D is the distance from the screen to the slits

is the wavelength of the source

d is the distance between the two slits

Now, You can increase fringe width by

1. Increasing wavelength of the source

2. Decreasing the distance between the two slits

3. Or you can move the screen away from the slits

Note:

All these are made basing on the fact both the light waves from different slits are nearly parallel with only small change of angle w.r.t horizontal