(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

Consider a plane wave (of wavelengthλ) incident on a wall at an angleΦ= 30. There are two slits in the wall separated by a distance d=10λ. Each slit has width a<<λ. Rays emerging from the slits propagate to a distant screen where an interference/diffraction pattern may be seen.

a. For rays emerging from the slits at the angle θ, calculate the total path length difference in terms ofθ,Φ, a, andλ

b. For what angleθwill we find the "central maximum"?

c. For what angleθwill we find the first interference minimum? Note: There will be a "first minimum" on each side of the central maximum. Find one of these.

2. Relevant equations

I'm not really sure. Maybe the equation for the intensity of a two-slit interference-diffraction pattern.

3. The attempt at a solution

The problem is, I have no idea what to make of a. I'm guessing for b and c, that I'm supposed to find the angles at which intensity will be a maximum and minimum, but I don't even have the path difference. I cannot figure out how the fact that the wave is incident affects the pattern.

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# Homework Help: Interference Diffraction

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