At what wavelength is visible light found?

• A. 700-1000 nm
• B. 400-700 nm
• C. 100-200 nm
• D. 1-10 nm

Answer: (B)

Visible light falls in the range where our eyes can detect wavelengths, roughly from 400 to 700 nanometers. Wavelengths shorter than that are ultraviolet, which we can’t see, and wavelengths longer than that are infrared, also not visible to us. The other options correspond to ultraviolet (100–200 nm), X-rays (1–10 nm), and infrared (700–1000 nm), so the visible range is 400–700 nm.