The pattern beyond the slit is usually not called an image; it is called a diffraction pattern. At this close range, you may be dealing with near-field Fresnel rather than conventional Fraunhofer scattering. You need to review the differences and apply the correct formulas, which are quite complex for Fresnel scattering.
(λ/D) is rather small in this case (0.01), so I expect there to be a bright spot about 10 cm wide 1 m beyond the slit, with some fringes at the edges.
I just don't have enough time to review all this for you. Sorry
Microwaves with λ = 1 mm are incident upon a 10 cm slit. At a distance of 1 m from the slit, what is the width of the slit's image?
The answer is supposed to be 10 cm.
I can't seem to get that though. Can someone explain?
2 answers
Apparently your book answer agrees with mine, but I should have used the terms Fresnel and Franhofer DIFFRACTION, not scattering. The type of diffraction that you have depends upon the dimensionless ratio
D/sqrt(λ R) If the ratio is <1, you have Fraunhofer scattering with uniformly spaced light and dark bands. In your case that ratio is much larger than 1. Most radiation will follow geometrical-optics ray paths to the near field screen
D/sqrt(λ R) If the ratio is <1, you have Fraunhofer scattering with uniformly spaced light and dark bands. In your case that ratio is much larger than 1. Most radiation will follow geometrical-optics ray paths to the near field screen
1 answer