Physics
Physics
Problem
Which part of the electromagnetic spectrum is routinely employed to sterilise surgical instruments because of its germicidal effect? a) Gamma rays b) Ultraviolet rays c) Microwaves d) Infrared raysIntuitive explanation
Ultraviolet (UV) radiation is the key here—specifically, UV-C light has the shortest wavelength and highest energy in the UV range, making it lethal to microorganisms. The core insight is that this high-energy radiation damages bacterial and viral DNA directly, preventing them from reproducing. Understanding why shorter wavelengths pack more destructive power helps you see why UV-C, not visible light or infrared, is the sterilization choice in hospitals.
Intuitive explanation
Ultraviolet (UV) radiation is the key here—specifically, UV-C light has the shortest wavelength and highest energy in the UV range, making it lethal to microorganisms. The core insight is that this high-energy radiation damages bacterial and viral DNA directly, preventing them from reproducing. Understanding why shorter wavelengths pack more destructive power helps you see why UV-C, not visible light or infrared, is the sterilization choice in hospitals.