A beam of white light is incident perpendicularly on a plane diffraction grating in air. The light is dispersed into several spectra on each side of the central (zero-order) maximum.
Answer the following about the pattern formed on a distant screen.
(a) Describe, in terms of wavelength and path difference, why the different visible colors appear at different angles relative to the central maximum.
(b) Rank the following colors according to their angular displacement from the central maximum for the first spectral order, from greatest to least: orange, violet, green, red. Justify your ranking.
(c) Explain why higher-order spectra (for example, second order compared to first order) appear farther from the center even for the same color.
(d) As more spectral orders appear, some overlap can occur. Describe qualitatively how this overlap arises and identify two experimental adjustments that could reduce or eliminate the overlap while still allowing bright, well-defined spectra.