A diffraction pattern is obtained using a beam of red light. Which one among the following will be the outcome if the red light is replaced by blue light ?

The diffraction pattern of light is governed by the relationship between the wavelength (λ) and the slit width. The angular spacing and fringe width in a diffraction pattern are directly proportional to the wavelength of the light used [t1][t2]. Red light has the longest wavelength in the visible spectrum, while blue light has a significantly shorter wavelength [t3]. According to the diffraction principles, a shorter wavelength results in a smaller angle of diffraction [t3]. Consequently, when red light is replaced by blue light, the diffraction fringes become narrower and the overall pattern becomes more crowded together on the screen [t3][t4]. This occurs because the spacing between the maxima and minima decreases as the wavelength decreases, leading to a more compact distribution of light bands compared to the broader pattern produced by red light [t3].

Sources

1. [1] https://en.wikipedia.org/wiki/Diffraction_from_slits