When an unpolarized beam of white light is passed through a double-slit apparatus, an interference pattern known as a "white light interference pattern" is observed on a screen. This pattern is a result of the superposition of light waves of different colors or wavelengths that make up white light.
The double-slit apparatus consists of two parallel slits that allow light to pass through. As the light passes through the slits, it diffracts and creates two coherent sources of light waves. These waves then spread out and interfere with each other as they overlap on a screen placed behind the slits.
Due to the different wavelengths present in white light, each wavelength will experience a slightly different interference pattern. This results in the separation of colors or wavelengths on the screen, with the shorter wavelengths (blue and violet) being more deviated and the longer wavelengths (red and orange) being less deviated. The resulting pattern on the screen appears as a series of colored fringes, with the central region showing white light.
The specific appearance of the interference pattern depends on factors such as the spacing between the slits, the distance from the slits to the screen, and the characteristics of the light source. It typically consists of a central bright fringe, surrounded by alternating dark and colored fringes, known as interference maxima and minima respectively.
Overall, the interference pattern produced by an unpolarized beam of white light in a double-slit apparatus exhibits a combination of colors due to the superposition of different wavelengths, resulting in a unique and intricate pattern of fringes.