Final answer:
To produce a rectangular intensity pattern on the screen with a larger width than height, you should use an aperture that is wider than it is high because the diffraction patterns' dimensions are inversely related to those of the aperture.
Step-by-step explanation:
If you wanted to make the intensity pattern on the screen rectangular, with a larger width than height, you should use a rectangular aperture that is wider than it is high. This is because diffraction patterns are inversely related to the dimensions of the aperture. According to the principles of diffraction, for a rectangular slit, the diffraction pattern in the direction perpendicular to the long side of the rectangle (the height in this case) will be wider.
Specifically, if we have a rectangular slit that is twice as wide as it is high, the central diffraction peak would be wider in the vertical direction compared to the horizontal direction because the slit height is the smaller dimension. This results in a diffraction pattern that has vertical fringes that are more spread out.
To see this effect visually, one might rely on simulations or experiments that illustrate how the diffraction patterns change with different aperture geometries. When light passes through an aperture, like a slit or a circular hole, it bends around the corners and edges, creating a pattern of bright and dark regions.
The spreading of light from these apertures accounts for the diffraction effects observed. In circular apertures, the central maximum is wider and brighter, with a similar principle applying to rectangular apertures; hence the orientation and proportions of the aperture affect the diffraction pattern.