jtbell said:Why would you expect it not to be the brightest?
(This is not meant to be a snarky response. I simply think it would be helpful to know if you have any specific thoughts about this so that people can address them directly instead of having to guess.)
The central fringe is brighter in the double slit experiment because it is the result of constructive interference between the two overlapping waves from the two slits. This creates a larger amplitude and therefore a more intense light compared to the other fringes.
The distance between the two slits plays a crucial role in determining the brightness of the central fringe. If the distance between the slits is increased, the central fringe becomes narrower and therefore appears brighter. On the other hand, if the distance is decreased, the central fringe becomes wider and less bright.
Yes, the brightness of the central fringe can be changed by adjusting the wavelength of the light source. This is because the spacing of the fringes is directly proportional to the wavelength of the light. So, a longer wavelength will result in a wider central fringe, and a shorter wavelength will result in a narrower central fringe.
The central fringe is always in the middle of the pattern in a double slit experiment because the two waves from the slits travel the same distance to reach the center of the screen. This ensures that the two waves are in phase and experience constructive interference, resulting in a bright central fringe.
Yes, the size of the slits does affect the brightness of the central fringe. A larger slit size will result in a wider central fringe, while a smaller slit size will result in a narrower central fringe. This is because the slit size determines the amount of diffraction that occurs, which in turn affects the spacing of the fringes and the brightness of the central fringe.