The spectrum of a certain substance in the visible region contains a number of spectral lines in the range from 400 nm to 600 nm with a minimum wavelength difference dl = 0.5 A. It is studied using a sufficiently large diffraction grating with a period d = 0.01 mm. Using a lens, the spectrum is projected onto a screen located in its focal plane and then viewed with the naked eye from the distance of best vision (L = 25 cm). Determine the minimum values of the lens diameter D and its focal length f, at k

Answer. Format gif