White light diffraction grating produces dispersed color spectra

Steps:

• Diffraction grating separates light wavelengths using d sinθ = mλ, where longer wavelengths (red) diffract more than shorter ones (violet).
• Red light forms symmetric bright spots at specific angles for each order m.
• White light contains all visible wavelengths, so each order spreads into a continuous spectrum from red to violet.
• Central maximum (m=0) remains white, while side orders show rainbow patterns without discrete dots.

Why D is correct:

• Shows central white spot with colored spectra spreading outward in each order, matching wavelength dispersion in the grating equation.

Why the others are wrong:

• A: Lacks color separation, showing only white spots like monochromatic light.
• B: Displays discrete colored dots instead of continuous spectra.
• C: Has asymmetric or incomplete dispersion, ignoring symmetric grating orders.

Final answer: D