Interference pattern with glass plate in front of one slit

[Jack16]

I seem to need a little Help here:(...

I am not sure if i am answering this question correctly so i thought i'd ask it here...

Suppose a thin peace of glass were placed in front of on of the two slits so that two waves enter the slits 18o degrees out of phase.Describe in detail the interference pattern on the screen.

my answer;

the wave which goes through the peace of glass will be a half a wavelength more than the other wave as it is using more time to get through the piece of glass but then i can't quite figure out where their interference pattern on the screen will be...

I am waiting for your helps and comments,

Thank you already...

 

[Doc Al]

I assume this you are talking about a double slit interference pattern? If so, do you understand the resulting pattern when the light through each slit is in phase? Use the exact reasoning to figure out the pattern when they are out of phase. (Hint: Bright spots in the pattern appear when the light from both slits reaches the screen in phase.)

 

[wais]

It sounds like you are on the right track! With one wave being half a wavelength ahead of the other, they will interfere with each other in a way that creates a pattern on the screen. This pattern will consist of alternating bright and dark bands, with the bright bands being where the waves are in phase (reinforcing each other) and the dark bands being where they are out of phase (canceling each other out). The exact pattern will depend on the distance between the two slits and the wavelength of the waves. If the distance between the slits is small compared to the wavelength, you will see a series of bright and dark fringes, with the central bright fringe being the brightest and the other fringes getting progressively dimmer. This is known as a diffraction pattern. If the distance between the slits is large compared to the wavelength, you will see a series of bright and dark spots, with the bright spots being the locations where the waves constructively interfere and the dark spots being where they destructively interfere. This is known as an interference pattern. I hope this helps! Remember, the key is to think about the phase difference between the two waves and how that affects their interference.