- #1

CricK0es

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## Homework Statement

Four equally spaced coherent light sources (n=4) with a wavelength of 500nm are separated by a distance d = 0.1mm. The interference pattern is viewed on a screen at a distance of 1.4m. Find the positions of the principle interference maxima and compare their width with that for just two sources (n=2) with the same spacing.[/B]

## Homework Equations

d . sinθ = mλ[/B]

## The Attempt at a Solution

The positions of the principle interference maxima occur (for both) at an angle given by

θ = arcsin( mλ / d ) // So I can find these quite easily using:

m =

**0, ±1, ±2 etc...**

λ = 500 . 10^-9 m

d = 1 . 10^-4 m

λ = 500 . 10^-9 m

d = 1 . 10^-4 m

However, I'm unsure how to find the widths of the maxima in question; for n=2 and n=4.

I would appreciate any guidance. Many thanks...

[/B]