What is UV spectrum range?

• A. 200 to 400 nm
• B. 400 to 200 nm
• C. 300 to 250 nm
• D. 100 to 300 nm

Answer: (C)

UV light is light with wavelengths shorter than visible light, which ends around 400 nm. The interval around 250 to 300 nm lies entirely within this ultraviolet region, sitting in the range where UV-C and the start of UV-B occur. This portion is a common window used in spectroscopy and disinfection contexts because many substances absorb strongly there and it’s well below the visible boundary. The other options either extend into the visible range or cover parts outside the typical UV window, so this 250–300 nm span best represents UV.