In the visible light spectrum, which color has the longest wavelength?
Q1. In the visible light spectrum, which color has the longest wavelength?
Answer: Red
Explanation: In the visible spectrum, red light has wavelengths of approximately 620–750 nm, the longest of any visible colour. Wavelength and frequency are inversely related (c = fλ), so red also has the lowest frequency among visible colours, while violet has the highest.